X-ray imaging apparatus and method for controlling the same

ABSTRACT

An imaging apparatus includes a camera to capture a camera image of a target disposed on an examination table; an X-ray source to generate and radiate X-rays; a memory to store imaging protocols; a display; and a controller. The controller is configured to receive information regarding a selection of an imaging protocol, identify a position of an imaging region of the target based on the camera image, the imaging region corresponding to the selection of the imaging protocol and the camera image being acquired with the examination table at a first distance from the X-ray source, control the display to display the camera image of the target and an indicator indicating the imaging region on the camera image based on the identified position, and control the X-ray source to radiate the X-rays toward the target disposed on the examination table at a second distance from the X-ray source.

CROSS-REFERENCE TO RELATED PATENT APPLICATIONS

This is a continuation of application Ser. No. 15/247,225 filed Aug. 25,2016, which claims priority from Korean Patent Application Nos.10-2015-0119877, 10-2015-0119879, 10-2015-0120578, 10-2015-0120577, and10-2016-0108157 filed Aug. 25, 2015, Aug. 25, 2015, Aug. 26, 2015, Aug.26, 2015, and Aug. 25, 2016, respectively, in the Korean IntellectualProperty Office. The disclosures of all of the above applications areincorporated by reference herein in their entireties.

BACKGROUND 1. Field

Embodiments of the present disclosure relate to an X-ray imagingapparatus and a method for controlling the same.

2. Description of the Related Art

An X-ray imaging apparatus is an apparatus that irradiates an objectwith X-rays and analyzes X-rays that have been transmitted through theobject to recognize an inner structure of the object. Since X-raytransmittance varies according to a tissue forming an object, an innerstructure of the object may be imaged using an attenuation coefficientwhich is a numerical value of X-ray transmittance.

Since an X-ray irradiation region may be adjusted using a collimator,the X-ray irradiation region should be accurately set in considerationof an X-ray imaging portion, a feature of an object, etc. to prevent theobject from being unnecessarily exposed to X-rays and beingunnecessarily irradiated with X-rays.

A part which is desired to be imaged may not be entirely captured by asingle imaging in some cases due to various reasons including a case inwhich the X-ray irradiation region is smaller than a portion to beimaged and a case in which a region to be detected by X-rays is smallerthan a portion to be imaged.

In these cases, one X-ray image of the desired part may be obtained bydividing the portion to be imaged into a plurality of regions, capturingeach of the plurality of regions by X-rays, and stitching the pluralityof X-ray images acquired together.

SUMMARY

Therefore, it is an aspect of the present disclosure to provide an X-rayimaging apparatus that uses a camera image to set various types ofparameters related to X-ray imaging including an X-ray irradiationregion and automatically controls X-ray imaging, and a method forcontrolling the same.

Additional aspects of the disclosure will be set forth in part in thedescription which follows and, in part, will be obvious from thedescription or may be learned by practice of the disclosure.

According to an embodiment, an X-ray imaging apparatus includes acapturing unit that captures a camera image, an X-ray source on which acollimator adjusting an X-ray irradiation region is mounted, a storageunit that maps and stores an X-ray imaging region for each of aplurality of X-ray imaging protocols, an input unit that receives aselection of one of the X-ray imaging protocols from the plurality ofX-ray imaging protocols, and a control unit that extracts an X-rayimaging region mapped to the selected X-ray imaging protocol from thecamera image and controls the collimator such that the X-ray irradiationregion corresponds to the extracted X-ray imaging region.

The input unit may receive a selection related to an X-ray imagingregion to be mapped for each of the plurality of X-ray imaging protocolsfrom a user.

The X-ray imaging apparatus may further include a display unit thatdisplays a graphical object having a shape of an object to receive aselection related to the X-ray imaging region and displays an imagingwindow designating the X-ray imaging region by overlapping the imagingwindow on the graphical object.

When at least one of a position and size of the imaging window isadjusted through the input unit, the control unit may store a regioncorresponding to at least one of the adjusted position and size of theimaging window in the storage unit as the X-ray imaging region.

The X-ray imaging apparatus may further include a display unit thatdisplays the camera image and displays the extracted X-ray imagingregion by overlapping the extracted X-ray imaging region on the cameraimage.

The display unit may display a protocol list for receiving a selectionof one X-ray imaging protocol from the plurality of X-ray imagingprotocols and may display the camera image when a camera image displaycommand is input through the input unit.

The input unit may receive a setting of an X-ray irradiation conditionfor each of the plurality of X-ray imaging protocols, and the storageunit may map and store the set X-ray irradiation condition for each ofthe plurality of X-ray imaging protocols.

When one of the plurality of X-ray imaging protocols is selected, thecontrol unit may perform X-ray imaging by applying an X-ray irradiationcondition mapped to the selected X-ray imaging protocol.

According to another embodiment, an X-ray imaging apparatus includes adisplay unit that displays a graphic user interface (GUI) for receivinga setting of an X-ray irradiation condition for each of a plurality ofsizes of an object, a storage unit that maps and stores the X-rayirradiation condition for each of the plurality of sizes of the objectaccording to an input, a capturing unit that captures a camera image,and a control unit that recognizes a size of an object shown in thecamera image and performs X-ray imaging by applying an X-ray irradiationcondition mapped to the recognized size of the object.

The display unit may display the recognized size of the object.

The storage unit may map and store and the X-ray irradiation conditionfor each of the plurality of sizes of the object and each of the X-rayimaging protocols.

When one of the plurality of X-ray imaging protocols is selected, thecontrol unit may perform X-ray imaging by applying an X-ray irradiationcondition mapped to the selected X-ray imaging protocol and therecognized size of the object.

According to yet another embodiment, an X-ray imaging apparatus includesa capturing unit that captures a camera image, an X-ray source on whicha light source irradiating an X-ray irradiation region with visible raysis mounted, a control unit that calculates a position of the X-rayirradiation region in the camera image based on coordinate informationof the X-ray source, extracts a light irradiation region which isirradiated with the visible rays displayed in the camera image,calculates a position of the extracted light irradiation region in thecamera image, and determines that calibration is required when theposition of the X-ray irradiation region and the position of the lightirradiation region do not match each other, and a display unit thatdisplays information related to the calibration when the calibration isrequired.

The display unit may display a first X-ray irradiation windowcorresponding to the calculated position of the X-ray irradiation regionand a second X-ray irradiation window corresponding to the calculatedposition of the light irradiation region.

When at least one of positions, forms, and sizes of the first X-rayirradiation window and the second X-ray irradiation window do not matcheach other, the control unit may determine that the calibration isrequired.

When the calibration is required, the control unit may calculate acalibration parameter based on a difference between the first X-rayirradiation window and the second X-ray irradiation window.

The display unit may display the calculated calibration parameter.

The control unit may automatically perform the calibration based on thecalculated calibration parameter.

The control unit may extract a boundary of an X-ray detector or amounting unit on which the X-ray detector is mounted shown in the cameraimage to extract a detector boundary line, and may determine whether theX-ray detector and the X-ray source are aligned with each other based onan X-ray irradiation window displayed at the calculated position of theX-ray irradiation region or the calculated position of the lightirradiation region and the extracted detector boundary line.

When intervals between a plurality of vertices forming the X-rayirradiation window and a plurality of vertices forming the detectorboundary line entirely match each other, the control unit may determinethat the X-ray detector and the X-ray source are aligned with eachother.

When a center of the X-ray irradiation window and a center of thedetector boundary line match each other, the control unit may determinethat the X-ray detector and the X-ray source are aligned with eachother.

The display unit may display the detector boundary line and the X-rayirradiation window by overlapping the detector boundary line and theX-ray irradiation window on the camera image.

The control unit may calculate a moving distance or a moving directionof the X-ray source or the X-ray detector for aligning the X-ray sourceand the X-ray detector with each other.

The control unit may move the X-ray source or the X-ray detector basedon the calculated moving distance or moving direction.

The display unit may display the calculated moving distance or movingdirection.

The display unit may display the X-ray irradiation window at thecalculated position of the X-ray irradiation region or the calculatedposition of the light irradiation region and the X-ray imaging apparatusmay further include an input unit that receives an adjustment commandfor adjusting a position or size of the X-ray irradiation window from auser.

When the X-ray irradiation window deviates from the boundary of theX-ray detector or the mounting unit on which the X-ray detector ismounted shown in the camera image due to an input adjustment command,the display unit may display a region deviating from the boundary.

According to still another embodiment, an X-ray imaging apparatus thatgenerates a single X-ray image by stitching a plurality of X-ray imagesof a plurality of divided regions together includes a capturing unitthat acquires a camera image, an X-ray source on which a collimatoradjusting an X-ray irradiation region is mounted, a display unit thatdisplays a plurality of divided windows showing sizes and positions ofthe plurality of divided regions by overlapping the plurality of dividedwindows on the camera image; and a control unit that controls thecollimator to adjust a width of the X-ray irradiation region of at leastone of the plurality of divided regions.

The X-ray imaging apparatus may further include an input unit thatreceives a command for controlling the width of the X-ray irradiationregion, and the control unit may control the collimator according to aninput command.

The control unit may control the collimator so that the width of theX-ray irradiation region matches a width of an object shown in thecamera image.

The control unit may extract an outline of the object from the cameraimage and determine the width of the X-ray irradiation region based on aboundary between the extracted outline and a background.

The X-ray imaging apparatus may further include a plurality of automaticexposure control (AEC) sensors that control an amount of X-rays radiatedfrom the X-ray source, and the control unit may select at least one ofthe plurality of AEC sensors based on the adjusted width of the X-rayirradiation region.

According to still another embodiment, an X-ray imaging apparatusgenerates a single X-ray image by stitching a plurality of X-ray imagesof a plurality of divided regions together, and includes a capturingunit that captures a camera image, a display unit that displays thecamera image, and a control unit that determines whether an overlappingregion in which the plurality of divided regions overlap the cameraimage is placed at a preset portion.

The control unit may move the overlapping region so that the overlappingregion is not placed at the preset portion.

The display unit may display the overlapping region by overlapping theoverlapping region on the camera image and may output a warning to auser when the overlapping region is placed at the preset portion.

The X-ray imaging apparatus may further include an input unit thatreceives a user command for moving the overlapping region.

According to an embodiment, a method for controlling an X-ray imagingapparatus includes mapping and storing an X-ray imaging region for eachof a plurality of X-ray imaging protocols, receiving a selection of oneof the X-ray imaging protocols from the plurality of X-ray imagingprotocols, extracting an X-ray imaging region mapped to the selectedX-ray imaging protocol from the camera image, and controlling acollimator such that an X-ray irradiation region corresponds to theextracted X-ray imaging region.

The mapping and storing of the X-ray imaging region may includereceiving a selection related to an X-ray imaging region to be mappedfor each of the plurality of X-ray imaging protocols from a user, andmapping and storing the X-ray imaging region for each of the pluralityof X-ray imaging protocols according to an input.

According to another embodiment, a method for controlling an X-rayimaging apparatus includes displaying a GUI for receiving a setting ofan X-ray irradiation condition for each of a plurality of sizes of anobject, mapping and storing the X-ray irradiation condition for each ofthe plurality of sizes of the object according to an input, capturing acamera image, recognizing a size of the object shown in the cameraimage, and performing X-ray imaging by applying an X-ray irradiationcondition mapped to the recognized size of the object.

The method may further include displaying the recognized size of theobject.

According to yet another embodiment, a method for controlling an X-rayimaging apparatus includes irradiating an X-ray irradiation region withvisible rays, capturing a camera image, calculating a position of theX-ray irradiation region in the camera image based on coordinateinformation of an X-ray source, extracting a light irradiation regionirradiated with visible rays displayed in the camera image, calculatinga position of the extracted light irradiation region in the cameraimage, determining that calibration is required when the position of theX-ray irradiation region and the position of the light irradiationregion do not match each other, and displaying information related tothe calibration when the calibration is required.

The method may further include extracting a boundary of an X-raydetector or a mounting unit on which the X-ray detector is mounted shownin the camera image to extract a detector boundary line, and determiningwhether the X-ray detector and the X-ray source are aligned with eachother based on an X-ray irradiation window displayed at the calculatedposition of the X-ray irradiation region or the calculated position ofthe light irradiation region and the extracted detector boundary line.

The method may further include displaying the X-ray irradiation windowat the calculated position of the X-ray irradiation region or thecalculated position of the light irradiation region, and receiving anadjustment command for adjusting a position or size of the X-rayirradiation window from a user.

When the X-ray irradiation window deviates from the boundary of theX-ray detector or the mounting unit on which the X-ray detector ismounted shown in the camera image due to an input adjustment command,the method may further include displaying a region deviating from theboundary.

According to still another embodiment, a method for controlling an X-rayimaging apparatus includes capturing a camera image, displaying aplurality of divided windows showing sizes and positions of a pluralityof divided regions by overlapping the plurality of divided windows onthe camera image, and controlling a collimator to adjust a width of anX-ray irradiation region of at least one of the plurality of dividedregions.

The method may further include receiving a command for controlling thewidth of the X-ray irradiation region, and the controlling thecollimator may include controlling the collimator according to an inputcommand.

The controlling the collimator may include controlling the collimatorsuch that the width of the X-ray irradiation region matches a width ofan object shown in the camera image.

The method may further include selecting at least one of a plurality ofAEC sensors for each of the plurality of divided regions based on theadjusted width of the X-ray irradiation region.

According to still another embodiment, a method for controlling an X-rayimaging apparatus includes capturing a camera image, displaying thecamera image, displaying a plurality of divided regions in whichstitching imaging will be performed by overlapping the plurality ofdivided regions on the camera image, and determining whether anoverlapping region in which the plurality of divided regions overlap thecamera image is placed at a preset portion.

The method may further include moving the overlapping region when theoverlapping region is placed at the preset portion.

BRIEF DESCRIPTION OF THE DRAWINGS

These and/or other aspects of the disclosure will become apparent andmore readily appreciated from the following description of theembodiments, taken in conjunction with the accompanying drawings ofwhich:

FIG. 1 is a control block diagram of an X-ray imaging apparatusaccording to an embodiment;

FIG. 2A is an exterior view illustrating a configuration of the X-rayimaging apparatus according to an embodiment;

FIG. 2B is an exterior view illustrating a sub-display device mounted onan X-ray source;

FIG. 3A is a view illustrating a configuration of a collimator;

FIG. 3B is a lateral cross-sectional view of a blade taken along lineA-A′ in FIG. 3A;

FIG. 4 shows an X-ray source viewed from the front;

FIGS. 5A and 5B are each a view illustrating an example of an automaticexposure control (AEC) sensor that may be used in the X-ray imagingapparatus according to an embodiment;

FIGS. 6 and 7 are each a view illustrating an example of a screendisplayed on a display unit of the X-ray imaging apparatus according toan embodiment;

FIG. 8A is a conceptual view illustrating light showing an X-rayirradiation region being radiated from the X-ray source;

FIG. 8B is a view illustrating an example in which a light irradiationregion is included in a camera image displayed on the display unit;

FIG. 9 is a view illustrating an example of displaying an X-rayirradiation window based on the light irradiation region;

FIG. 10 is a view illustrating an X-ray irradiation window generatedusing coordinate information and an X-ray irradiation window generatedthrough image processing;

FIGS. 11, 12, 13, 14, and 15 are views illustrating a method foraligning the X-ray source and an X-ray detector of the X-ray imagingapparatus according to an embodiment to each other;

FIG. 16 is a view illustrating an example in which an X-ray irradiationwindow displayed on the display unit of the X-ray imaging apparatusaccording to an embodiment is deviated from a boundary of the X-raydetector;

FIGS. 17, 18, and 19 are views illustrating examples of presetting animaging region according to an imaging protocol;

FIG. 20 is a view illustrating information stored in a storage unit;

FIG. 21 is a view illustrating a process of extracting an imaging regioncorresponding to an imaging protocol from an image of an object;

FIG. 22 is a view illustrating a camera image in which an extractedimaging region is displayed;

FIG. 23 is a view illustrating an operation of presetting informationrelated to a size of the object;

FIG. 24 is a view illustrating pre-stored information related to thesize of the object;

FIG. 25 is a view illustrating a screen through which an X-rayirradiation condition may be set for each of a plurality of sizes of anobject;

FIG. 26 is a view illustrating an operation of automatically determininga size of an object based on a camera image;

FIG. 27 is a view illustrating an example of a stitched-together image;

FIG. 28 is a view illustrating an example in which an imaging region isdivided to perform stitching imaging;

FIG. 29 is a view illustrating overlapping regions between each of aplurality of divided regions;

FIGS. 30 and 31 are views illustrating an operation in which overlappingregions are automatically adjusted;

FIGS. 32 and 33 are views related to a case in which a user directlydesignates a stitching region;

FIGS. 34A, 34B, 35, and 36 are views illustrating a screen that allows auser to set a width of an X-ray irradiation region of each of aplurality of divided regions in the X-ray imaging apparatus according toan embodiment;

FIGS. 37 and 38 are views illustrating a screen that allows the user toselect an AEC sensor in the X-ray imaging apparatus according to anembodiment;

FIGS. 39A, 39B, and 39C are views related to a case in which stitchingimaging is performed by controlling a tilt angle of the X-ray source inthe X-ray imaging apparatus according to an embodiment;

FIG. 40 is a view illustrating an operation of determining a movement ofan object using a camera image;

FIGS. 41 and 42 are views illustrating controlling in a case in whichre-imaging is performed after stitching imaging is stopped while dividedimaging is partially completed;

FIG. 43 is a flowchart illustrating an example of a method for verifyingan X-ray irradiation region in a method for controlling an X-ray imagingapparatus according to an embodiment;

FIG. 44 is a flowchart illustrating an example of a method for aligningan X-ray source and an X-ray detector with each other in the method forcontrolling an X-ray imaging apparatus according to an embodiment;

FIG. 45 is a flowchart related to a method for setting an imagingprotocol in the method for controlling an X-ray imaging apparatusaccording to an embodiment;

FIG. 46 is a flowchart related to a method for determining whetherdivided imaging has stopped according to a movement of an object in themethod for controlling an X-ray imaging apparatus according to anembodiment;

FIG. 47 is a flowchart related to a case of resuming stitching imagingin the method for controlling an X-ray imaging apparatus according to anembodiment;

FIG. 48 is a flowchart related to a method for controlling anoverlapping region in the method for controlling an X-ray imagingapparatus according to an embodiment; and

FIG. 49 is a flowchart related to a method for presetting a size of anobject in the method for controlling an X-ray imaging apparatusaccording to an embodiment.

DETAILED DESCRIPTION

Hereinafter, embodiments related to an X-ray imaging apparatus and amethod for controlling the same according to an aspect will be describedin detail with reference to the accompanying drawings.

In the following description, like drawing reference numerals are usedfor like elements, even in different drawings. The matters defined inthe description, such as detailed construction and elements, areprovided to assist in a comprehensive understanding of the exemplaryembodiments. However, it is apparent that the exemplary embodiments canbe practiced without those specifically defined matters. Also,well-known functions or constructions are not described in detail sincethey would obscure the description with unnecessary detail.

FIG. 1 is a control block diagram of an X-ray imaging apparatusaccording to an embodiment, FIG. 2A is an exterior view illustrating aconfiguration of the X-ray imaging apparatus according to an embodiment,and FIG. 2B is an exterior view illustrating a sub-display devicemounted on an X-ray source. An exterior illustrated in FIG. 2A is anexample of the X-ray imaging apparatus and relates to a ceiling typeX-ray imaging apparatus in which an X-ray source is connected to aceiling of an examination room.

Referring to FIG. 1, an X-ray imaging apparatus 100 according to anembodiment includes an X-ray source 110 that generates and radiatesX-rays, a display unit 150, e.g., a display, display device, monitor, ora display screen, that displays a screen for setting a size of anobject, a screen for setting an imaging protocol, an image captured by acapturing unit 120, e.g., an imaging device, a camera, etc., a screenfor setting an X-ray irradiation condition, and the like, an input unit160 that receives control commands including a command for setting asize of the object, a command for setting the imaging protocol, acommand for setting the X-ray irradiation condition, etc. from a user, astorage unit 170 that stores information related to the size of theobject, the imaging protocol, and the X-ray irradiation condition, and acontrol unit 140, i.e., a controller, that controls an overall operationof the X-ray imaging apparatus 100.

In addition, the X-ray imaging apparatus 100 may further include acommunication unit 130 that communicates with an external device.

The control unit 140 may control a time point at which X-rays areradiated from the X-ray source 110, an X-ray irradiation condition, etc.according to a command input by the user and may generate a medicalimage using data received from an X-ray detector 200.

In addition, the control unit 140 may also control a position or anorientation of the X-ray source 110 or mounting units 14 and 24 on whichthe X-ray detector 200 is mounted according to positions of an imagingprotocol and an object P.

The control unit 140 may include a memory in which a program forperforming the operations described above and operations, which will bedescribed below, is stored and a processor that executes the storedprogram. The control unit 140 may include one processor ormicroprocessor, or a plurality of processors or microprocessors. In thelatter case, the plurality of processors or microprocessors may beintegrated on one chip or may be physically separated from each other.

When the control unit 140 includes the plurality of processors and aplurality of memories, some of the memories and the processors may beprovided at a work station 180, and the remaining memories andprocessors may be provided in other devices such as a sub-display device(80, see FIG. 2A) or a moving carriage (40, see FIG. 2A). For example, aprocessor provided in the work station 180 may perform controlling ofimage processing and the like for generating a medical image, and aprocessor provided in the sub-display device or the moving carriage mayperform controlling related to a movement of the X-ray source 110 or theX-ray detector 200.

The X-ray imaging apparatus 100 may be connected to an external device(e.g., an external server 310, a medical apparatus 320, a portableterminal 330 (such as a smartphone, a tablet personal computer (PC), anda wearable device)) via the communication unit 130 and transmit orreceive data therewith.

The communication unit 130 may include one or more elements that enablecommunicating with an external device. For example, the communicationunit 130 may include at least one of a short-distance communicationmodule, a wired communication module, and a wireless communicationmodule. In addition, the communication unit 130 may further include aninner communication module that enables communication between elementsof the X-ray imaging apparatus 100.

In addition, the communication unit 130 may receive a control signalfrom an external device and transmit the received control signal to thecontrol unit 140 such that the control unit 140 may control the X-rayimaging apparatus 100 according to the received control signal.

In addition, the control unit 140 may also control an external deviceaccording to the control signal from the control unit 140 bytransmitting the control signal to the external device via thecommunication unit 130. For example, the external device may processdata of the external device according to the control signal from thecontrol unit 140 received via the communication unit 130. Since aprogram capable of controlling the X-ray imaging apparatus 100 may beinstalled in the external device, the program may include an instructionthat executes some or all operations of the control unit 140.

The program may be pre-installed in the portable terminal 330, and theprogram may also be downloaded and installed by a user of the portableterminal 330 from a server that provides applications. The server thatprovides applications may include a recording medium in which thecorresponding program is stored.

Referring to FIG. 2A, a guide rail 30 may be installed on a ceiling ofan examination room in which the X-ray imaging apparatus 100 isdisposed, the X-ray source 110 may be connected to the moving carriage40 moving along the guide rail 30 to move the X-ray source 110 to aposition corresponding to the object P, and the moving carriage 40 andthe X-ray source 110 may be connected via a post frame 50 to adjust aheight of the X-ray source 110.

Since the X-ray source 110 may be moved automatically or manually, theX-ray imaging apparatus 100 may further include a driving unit such as amotor that provides power which moves the X-ray source 110 when theX-ray source 110 automatically moves.

The work station 180 may be provided in a space separated from a spacein which the X-ray source 110 is disposed by a shielding curtain B. Thework station 180 may include an input unit 181 that receives a commandfrom the user and a display unit 182 that displays information.

The input unit 181 may receive a command for controlling an imagingprotocol, an X-ray irradiation condition, a time point at which X-raysare radiated, a position of the X-ray source 110, and the like. Theinput unit 181 may include a keyboard, a mouse, a touch screen, a voicerecognizer, and the like.

The display unit 182 may display a screen for guiding an input by theuser, an X-ray image, a screen showing a state of the X-ray imagingapparatus 100, etc.

Meanwhile, the display unit 150 and the input unit 160 described withreference to FIG. 1 may be respectively implemented as the display unit182 and the input unit 181 provided in the work station 180, may also berespectively implemented as a sub-display unit 81 and a sub-input unit82 provided in the sub-display device 80, and may also be implemented asa display unit and an input unit provided in a mobile device such as atablet PC and a smartphone.

The X-ray detector 200 may be implemented with a fixed type X-raydetector fixed to a stand 20 or a table 10, may be detachably mounted onthe mounting units 14 and 24, and may also be implemented with aportable X-ray detector which is usable at any position. The portableX-ray detector may be implemented as a wired type or a wireless typeaccording to a way of transmitting data and a way of supplying power.

Since the X-ray detector 200 may also move automatically or manually,the X-ray imaging apparatus 100 may further include a driving unit suchas a motor that provides power which moves the mounting units 14 and 24when the X-ray detector 200 moves automatically.

The X-ray detector 200 may either be included or not included as anelement of the X-ray imaging apparatus 100. In the latter case, theX-ray detector 200 may be registered in the X-ray imaging apparatus 100by the user. In addition, in both cases, the X-ray detector 200 may beconnected to the control unit 140 via the communication unit 130 toreceive a control signal or transmit image data.

The sub-display device 80 that provides the user with information andreceives a command from the user may be provided at one side of theX-ray source 110, and some or all of the functions performed by theinput unit 181 and the display unit 182 of the work station 180 may beperformed by the sub-display device 80.

When all or some of the elements of the control unit 140 and thecommunication unit 130 are provided to be separate from the work station180, the elements may be included in the sub-display device 80 providedat the X-ray source 110.

The user may input various types of information or commands related toX-ray imaging by manipulating the sub-input unit 82 illustrated in FIG.2B or touching the sub-display unit 81 illustrated in FIG. 2B.

For example, the user may input a position to which the X-ray source 110will be moved through the sub-input unit 82 or the sub-display unit 81.

Although FIG. 2A illustrates a fixed type X-ray imaging apparatusconnected to the ceiling of the examination room, the X-ray imagingapparatus 100 may include X-ray imaging apparatuses with variousstructures such as a C-arm type X-ray imaging apparatus and a mobileX-ray imaging apparatus within the scope that is self-evident to thoseof ordinary skill in the art.

Meanwhile, the X-ray source 110 may include an X-ray tube that generatesX-rays, a collimator that adjusts a region to be irradiated with X-raysgenerated by the X-ray tube, and the capturing unit 120 that captures acamera image. Hereinafter, these will be described in detail withreference to the drawings.

FIG. 3A is a view illustrating a configuration of a collimator, and FIG.3B is a lateral cross-sectional view of a blade taken along line A-A′ inFIG. 3A.

Referring to FIG. 3A, a collimator 113 may include one or more movableblades 113 a, 113 b, 113 c, and 113 d, and the one or more blades mayabsorb X-rays by being formed of a material having a high bandgap. Anirradiation range of X-rays may be adjusted as the one or more bladesmove, and the collimator 113 may further include a motor that providespower to each of the one or more blades.

The control unit 140 calculates a movement amount of each of the one ormore blades corresponding to a set X-ray irradiation region andtransmits a control signal for moving the one or more blades by thecalculated movement amount to the collimator 113.

For example, the collimator 113 may include the four blades 113 a, 113b, 113 c, and 113 d each having a quadrilateral shape. The first blade113 a and the third blade 113 c are movable in both directions along anx-axis, and the second blade 113 b and the fourth blade 113 d aremovable in both directions along a y-axis.

In addition, each of the four blades 113 a, 113 b, 113 c, and 113 d maymove separately, or the first blade 113 a and the third blade 113 c maymove together as a set and the second blade 113 b and the fourth blade113 d may move together as a set.

X-rays may be radiated through a slot R formed by the four blades, andcollimation may be performed by passing the X-rays through the slot R.Consequently, in this embodiment, the slot R is referred to as acollimation region, and an X-ray irradiation region signifies a regionin which X-rays that have passed through the collimation region R areincident on an object 1 or the X-ray detector 200.

Referring to FIG. 3B, the collimator 113 is disposed in front of anX-ray tube 111. Here, a direction toward a front of the X-ray tube 111signifies a direction in which X-rays are radiated. An X-ray irradiationregion E of X-rays radiated from a focal point 2 of the X-ray tube 111is limited by the collimator 113, and scattering of the X-rays isreduced.

Among the X-rays radiated from the X-ray tube 111, X-rays incident onthe blades 113 a, 113 b, 113 c, and 113 d are absorbed into the blades,and X-rays that have passed through the collimation region R areincident on the X-ray detector 200. Here, a description will assume thatan object does not exist.

When X-rays scatter in the form of cone beams, the X-ray irradiationregion E is larger than the collimation region R. A desired range of theX-ray irradiation region E may be irradiated with X-rays by the controlunit 140 by adjusting the collimation region R based on a relationbetween the two regions.

Although the collimator 113 has been described as having four blades ina quadrilateral shape in the example above, this is merely an examplethat is applicable to the X-ray imaging apparatus 100, and the number orshape of blades included in the collimator 113 is not limited thereto.

FIG. 4 shows an X-ray source viewed from the front.

Referring to FIG. 4, the collimator 113 may be disposed in front of theX-ray source 110, and the capturing unit 120 may be embedded in a regionadjacent to the collimator 113.

The capturing unit 120 may capture a video by being be implemented as acamera such as a charge-coupled device (CCD) camera and a complementarymetal oxide silicon (CMOS) camera. Alternatively, the capturing unit 120may also capture still images at short intervals.

While the X-ray source 110 captures an X-ray image of an object, thecapturing unit 120 captures a real image of the object, e.g., a target.In an embodiment to be described below, an image captured by the X-raysource 110 will be referred to as an X-ray image, and an image capturedby the capturing unit 120 will be referred to as a camera image. Thecamera image may either include or not include an object. That is, thecamera image may be captured while the object 1 is disposed in front ofthe X-ray detector 200, and the camera image may also be captured whilethe object 1 does not exist.

The capturing unit 120 may be disposed at a position at which a portionof an object to be imaged by X-rays may be captured. For example, thecapturing unit 120 may be mounted on the X-ray source 110 in a directionthat is the same as a direction in which X-rays are radiated from theX-ray source 110. When the capturing unit 120 is mounted on the X-raysource 110, the user may more easily set settings related to an X-rayimage while looking at a camera image since an offset between a regionshown in the X-ray image and a region shown in the camera image isreduced. A position on which the capturing unit 120 is mounted may besuitably determined within a range that minimizes the offset between theregion shown in the X-ray image and the region shown in the camera imageand that does not affect X-ray imaging.

Since a housing 110 a may be formed in front of the collimator 113, thehousing 110 a may be formed with a material such as a transparent resinor glass to minimize its influence on X-rays radiated from the X-raytube 111.

In addition, a guideline GL in a cross shape may be displayed on thehousing formed in front of the collimator 113. When the X-rayirradiation region E is irradiated with visible rays by a collimatorlamp embedded in the X-ray source 110, a shadow of the guideline GL maybe displayed at the center of the X-ray irradiation region E and theuser may intuitively recognize a position of the X-ray irradiationregion E by looking at the shadow of the guideline GL.

The capturing unit 120 may be mounted on an inner portion of the housing110 a as illustrated in FIG. 4. Alternatively, the capturing unit 120may also be mounted on an outer portion of the housing 110 a. Here, thecapturing unit 120 may be mounted on a bezel provided at a circumferenceof the housing 110 a. However, since an embodiment of the X-ray imagingapparatus 100 is not limited thereto, the capturing unit 120 may bemounted on any position so long as an image of an object can be capturedat the position.

In addition, the capturing unit 120 may also be implemented as a stereocamera. In this case, cameras may be disposed at both left and rightsides in front of the X-ray source 110. When the capturing unit 120 isimplemented as a stereo camera, information on a depth of a camera imagemay be acquired and accuracy in image recognition and reliability ofvarious types of information calculated based on the camera image may beimproved using the depth information.

FIGS. 5A and 5B are views each illustrating an example of an automaticexposure control (AEC) sensor that may be used in the X-ray imagingapparatus according to an embodiment.

To prevent an object from being excessively irradiated with X-rays, theX-ray imaging apparatus 100 may perform AEC. For this, an AEC sensormodule 26 that detects a dose of X-rays may be provided in the mountingunit 24 as illustrated in FIG. 5A. Although the AEC sensor module 26 isdescribed using the mounting unit 24 of the stand 20 in this example, anAEC sensor module may also be provided at the mounting unit 14 of thetable 10.

FIG. 5A shows the mounting unit 24 viewed from the front. The AEC sensormodule 26 may be provided inside the mounting unit 24 and may include aplurality of AEC sensors 26 a, 26 b, and 26 c that independently detecta dose of X-rays. For example, each of the AEC sensors may beimplemented as an ionization chamber.

The most accurate AEC is possible when an AEC sensor is disposed at thecenter of an X-ray imaging portion. Markers Ma, Mb, and Mc thatrespectively show positions of the plurality of AEC sensors 26 a, 26 b,and 26 c may be provided at a surface of the mounting unit 24 toposition the center of the X-ray imaging portion at a positioncorresponding to the AEC sensor or select an AEC sensor disposed at thecenter of the X-ray imaging portion.

Although a total of three AEC sensors, two at an upper side and one at alower side, are illustrated as being provided in FIG. 5A, this is merelyan example. Less than or more than three AEC sensors may also beprovided, and the AEC sensors may also be arranged in a different way.

Referring to FIG. 5B, the AEC sensor module 26 may also be disposed infront of the X-ray detector 200. A direction toward the front of theX-ray detector 200 signifies a direction in which X-rays are incident.FIG. 5B shows the AEC sensor module 26 disposed in front of the X-raydetector 200 viewed from the side.

A current may be generated when X-rays are incident on an AEC sensor,and the AEC sensor may transmit a signal corresponding to the generatedcurrent to the control unit 140. The signal transmitted to the controlunit 140 may be an amplified and digitized signal.

Based on the transmitted signal, the control unit 140 determines whethera dose of X-rays currently incident exceeds a critical dose. When thedose of the X-rays exceeds the critical dose, a cut-off signal may betransmitted to a high-voltage generator 101 that supplies a high voltageto the X-ray tube 111 to stop generation of the X-rays.

Meanwhile, a grid that prevents X-rays from scattering may also bedisposed in front of the AEC sensor module 26. Some of the X-raysradiated from the X-ray source 110 may deviate from their original pathand scatter by colliding against dust particles in the air or substancesforming an object before reaching the X-ray detector 200. When thescattered X-rays are incident on the X-ray detector 200, the scatteredX-rays have a negative influence on the quality of an X-ray image suchas degrading the contrast of an X-ray image.

The grid has a structure in which shielding substances such as lead (Pb)that absorb X-rays are arranged. Among radiated X-rays, X-rays advancingin their original direction, i.e., X-rays moving forward, pass throughportions between the shielding substances and are incident on the X-raydetector 200, and scattered X-rays collide with the shielding substancesand are absorbed into the shielding substances.

The shielding substances may be arranged in a linear structure and alsoin a cross-like structure. In addition, the shielding substances may betilted in a direction similar to that in which the X-rays are radiatedand may be densely arranged or arranged in parallel.

Although not illustrated in the drawings, a driving unit that includes amotor which may mechanically move the grid may be disposed inside themounting unit 24. Consequently, an angle or a central position of thegrid may be adjusted by transmitting a control signal to the drivingunit from the outside.

Meanwhile, although the AEC sensor module 26 has been described in theexample as being provided at the mounting unit 24, the AEC sensor module26 may also be integrally provided with the X-ray detector 200.

FIGS. 6 and 7 are each a view illustrating an example of a screendisplayed on a display unit of the X-ray imaging apparatus according toan embodiment.

As illustrated in FIG. 6, a settings window 151 for setting an x-ayirradiation condition and a work list 155 may be displayed on a screen150 a of the display unit 150.

The work list 155 may include a study list 155 a from which a study maybe selected and a protocol list 155 b from which an imaging protocol maybe selected. A study may refer to a set of X-ray images related to eachother. When any one study is selected from the study list 155 a, theprotocol list 155 b from which an imaging protocol to be applied to theselected study may be selected is displayed.

An X-ray imaging region may change for each imaging protocol, and asuitable X-ray irradiation condition may change for each X-ray imagingregion. The imaging protocol may be determined according to an X-rayimaging portion, a posture of an object, and the like. For example,imaging protocols may include whole body anterior-posterior (AP), wholebody posterior-anterior (PA), and whole body lateral (LAT), may alsoinclude chest AP, chest PA, and chest LAT, and may also include longbone AP, long bone PA and long bone LAT for long bones such as a legbone. In addition, the imaging protocols may also include abdomen erect.

A graphic user interface (GUI) in which an X-ray irradiation conditionmay be set may be displayed on the settings window 151. The GUI mayinclude a plurality of graphical objects which may be used to setvarious X-ray irradiation conditions. In this embodiment, objects suchas buttons and icons displayed on the display unit 150 to be used inproviding information or receiving a control command from the user mayall be referred to as graphical objects.

Since the graphical objects displayed on the settings window 151 areused to receive a command for setting an X-ray irradiation conditionfrom the user, the graphical objects may be implemented as buttonsrespectively corresponding to various X-ray irradiation conditions.

For example, a tube voltage setting button 151 a for receiving a tubevoltage setting, a tube current setting button 151 b for receiving atube current setting, and an exposure time setting button 151 c forreceiving an X-ray exposure time setting may be displayed. The user mayselect each of the buttons to set an X-ray irradiation condition to havea desired value. The buttons may be selected by clicking or touchingdepending on a type of the input unit 160.

According to an embodiment, the tube voltage setting button 151 a mayseparately include a button for increasing a tube voltage and a buttonfor decreasing the tube voltage, the tube current setting button 151 bmay separately include a button for increasing a tube current and abutton for decreasing the tube current, and the exposure time settingbutton 151 c may separately include a button for increasing an exposuretime and a button for decreasing the exposure time.

In addition, a capture position setting button 151 d for receiving asetting related to whether X-ray imaging will be performed at the stand20 or at the table 10, an object size selection button 151 e forreceiving a selection related to a size of a patient, a collimatorsetting button 151 f for receiving a setting related to a size of thecollimator 113, an AEC selection button 151 g for receiving a selectionrelated to an AEC sensor, a sensitivity setting button 151 h forreceiving a setting related to sensitivity, a button 151 i for receivinga setting related to density, a grid selection button 151 j forreceiving a selection related to the grid, a filter selection button 151k for receiving a selection related to a filter, a focal point selectionbutton 151 r for receiving a selection related to a size of a focalpoint, etc. may be further displayed.

The buttons may be implemented as shapes formed of pictures, letters,symbols, etc. The user may select any one shape by moving a cursor andclicking the corresponding shape or touching and manipulating the shape.Accordingly, a setting corresponding to the selected shape may bechanged.

Meanwhile, when a selection related to a size of a patient is input, anX-ray irradiation condition mapped as a default for the correspondingsize may be set. For this, the storage unit 170 may store a database inwhich an X-ray irradiation condition for each of a plurality of sizes ofa patient is mapped.

When the user selects a size of a patient, X-ray irradiation conditionssuch as a tube voltage, a tube current, and an exposure time mapped as adefault for the corresponding size are displayed in the settings window151. The mapped X-ray irradiation conditions may be applied withoutchange, or the user may select a button corresponding to each of theX-ray irradiation conditions and set each of the X-ray irradiationconditions again according to the method described above. Here, the usermay set each of the X-ray irradiation conditions again with reference todefault X-ray irradiation conditions displayed in the settings window151.

In addition, an X-ray imaging region may change for each imagingprotocol, and a suitable X-ray irradiation condition may change for eachX-ray imaging region. Consequently, an X-ray irradiation condition maybe set differently according to an imaging protocol selected from thework list 155 and a size of an object selected from the settings window151.

The types and arrangements of the graphical objects displayed in thesettings window 151 described above are all illustrative. Some of theabove may be omitted according to a designer's choice, a graphicalobject other than the above for changing a setting may be furtherprovided, and the above may be provided in arrangements different fromthose in the example described above.

When the setting of X-ray irradiation conditions is completed, the usermay select an exposure button 151 l to perform X-ray imaging and mayselect a reset button 151 m when attempting to initialize settings.

Meanwhile, to obtain information required for performing X-ray imaging,the capturing unit 120 may capture a camera image while the X-ray source110 is facing the X-ray detector 200. In this case, the X-ray detector200 or the mounting units 14 and 24 on which the X-ray detector 200 ismounted may be covered by the object 1 and may not be shown in thecamera image. Conversely, when a camera image is captured while theobject 1 is not disposed in front of the X-ray detector 200, the X-raydetector 200 or the mounting units 14 and 24 on which the X-ray detector200 is mounted may be shown in the camera image. A captured camera image152 may be displayed at one side of the settings window 151 asillustrated in FIG. 7.

The work list 155 illustrated in FIG. 6 and the camera image 152illustrated in FIG. 7 may be switched with each other. The work list 155may be switched to the camera image 152 when a camera image button I isselected while the work list 155 is displayed, and the camera image 152may be switched to the work list 155 when a close button 152 b isselected while the camera image 152 is displayed. Alternatively, whenthe selected imaging protocol needs stitching imaging, the work list 155may be switched to the camera image 152 automatically and then screensregarding stitching imaging described below may be displayed.

Referring to FIG. 7, an X-ray irradiation window B1 may be displayed bybeing overlapped on the X-ray detector 200 or the mounting unit 24 shownin the camera image 152. In this example, the X-ray detector 200 ismounted in the mounting unit 24, and the mounting unit 24 is displayedin the camera image.

The X-ray irradiation window B1 is a tool for showing a region at whichX-rays radiated from the X-ray source 110 reach the X-ray detector 200,i.e. the X-ray irradiation region E. The control unit 140 may calculatethe X-ray irradiation region E according to an algorithm, which will bedescribed below, and display the X-ray irradiation window B1 that showsa size and a position of the calculated X-ray irradiation region E inthe camera image 152 to provide the user with information on the sizeand the position of the calculated X-ray irradiation region E. Here, asize and a position of the X-ray irradiation window B1 is relative tothe mounting unit 24 shown in the camera image 152.

The user may adjust the position, the size, or a form of the X-rayirradiation window B1 displayed on the display unit 150 by inputting apredetermined operation command through the input unit 160, and thecontrol unit 140 may control the collimator 113 according to the inputoperation command to adjust the X-ray irradiation region E.

The X-ray irradiation window B1 displayed on the display unit 150 andthe actual X-ray irradiation region E may be different from each otherdue to various errors of an apparatus. That is, the X-ray irradiationwindow B1 may not accurately reflect the position or the size of theactual X-ray irradiation region E in some cases. Consequently, the X-rayimaging apparatus 100 may perform a procedure for verifying whether theX-ray irradiation window B1 illustrated in FIG. 7 accurately reflectsthe actual X-ray irradiation region E.

First, a method for displaying the X-ray irradiation window B1 on thedisplay unit 150 will be described.

The control unit 140 may display the X-ray irradiation window B1 on thedisplay unit 150 using pre-stored coordinate information of the X-rayimaging apparatus 100. The control unit 140 may include pre-storedpieces of information on a distance between the X-ray source 110 and theX-ray detector 200, a form and an area of the slot R formed by thecollimator 113, a distance from the X-ray tube 111 to the slot R of thecollimator 113, etc., or may calculate the above pieces of informationfrom pre-stored information.

The control unit 140 may calculate three-dimensional coordinates of theX-ray irradiation region E formed at a surface of the mounting unit 24using the above pieces of information. The three-dimensional coordinatesof the X-ray irradiation region E calculated by the control unit 140correspond to coordinates on a global coordinate system of a space inwhich the X-ray imaging apparatus 100 is disposed. The coordinateinformation of the X-ray irradiation region E calculated by the controlunit 140 may include at least coordinates of vertices of the X-rayirradiation region E.

The X-ray irradiation window B1 showing the X-ray irradiation region isdisplayed by being overlapped on the camera image 152. Since the X-rayirradiation window B1 displayed by being overlapped on the camera image152 is based on a two-dimensional coordinate system, the control unit140 converts the calculated information on three-dimensional coordinatesof the X-ray irradiation region E into coordinates based on atwo-dimensional image coordinate system.

In addition, the camera image 152 illustrated in FIG. 7 is an imageacquired by the capturing unit 120, and a coordinate system of thecapturing unit 120 is different from the global coordinate system. Thus,to covert the information on three-dimensional coordinates of the X-rayirradiation region E into coordinates based on the two-dimensional imagecoordinate system as described above, the global coordinate systemshould be converted into a camera coordinate system. That is, the globalcoordinate system should be converted into the camera coordinate system,and the information on three-dimensional coordinates converted intocoordinates based on the camera coordinate system should be convertedinto coordinates based on the two-dimensional image coordinate system.

An equation for converting coordinates (X, Y, and Z) based on the globalcoordinate system into coordinates (x, y) based on the two-dimensionalcoordinate system may be expressed as Equation 1. The control unit 140may convert three-dimensional coordinates of the X-ray irradiationregion formed at the X-ray detector 200 into two-dimensional coordinatesof the X-ray irradiation window B1 to be displayed on the display unit150 using the relation between the global coordinate system and thetwo-dimensional coordinate system expressed by Equation 1 below. Thecontrol unit 140 may use the two-dimensional coordinates converted asabove to display the X-ray irradiation window B1 by overlapping theX-ray irradiation window B1 on the camera image displayed on the displayunit 150.

$\begin{matrix}{\begin{bmatrix}x \\y \\1\end{bmatrix} = {\begin{bmatrix}f_{x} & 0 & c_{x} \\0 & f_{y} & c_{y} \\0 & 0 & 1\end{bmatrix} \cdot {\quad{\begin{bmatrix}{\cos \; B\; \cos \; C} & {{- \cos}\; B\; \sin \; C} & {\sin \; B} & t_{1} \\{{\sin \; A\; \sin \; B\; \cos \; C} + {\cos \; A\; \sin \; C}} & {{{- \sin}\; A\; \sin \; B\; \sin \; C} + {\cos \; A\; \cos \; C}} & {{- \sin}\; A\; \cos \; B} & t_{2} \\{{{- \cos}\; A\; \sin \; B\; \cos \; C} + {\sin \; A\; \sin \; C}} & {{\cos \; A\; \sin \; B\; \sin \; C} + {\sin \; A\; \cos \; C}} & {\cos \; B\; \cos \; B} & t_{3}\end{bmatrix} \cdot {\quad{\quad\begin{bmatrix}X \\Y \\Z \\1\end{bmatrix}}}}}}} & {< {{Equation}\mspace{14mu} 1} >}\end{matrix}$

In Equation 1, x and y represent coordinates of a two-dimensional imagesensor, i.e., coordinates of an image coordinate system, and X, Y, and Zrepresent coordinates of the global coordinate system.

In Equation 1 above, a first matrix at the right side includes innerparameters of the capturing unit 120 such as a focal length and aprincipal point of the capturing unit 120 as its elements. In Equation1, fx and fy represent the focal length of the capturing unit 120, andcx and cy represent the principal point of the capturing unit 120.

In Equation 1, a second matrix at the right side is a matrix to allowthe global coordinate system to match the camera coordinate system andincludes outer parameters of the capturing unit 120 such as a directionin which the capturing unit 120 is installed as its elements.

In Equation 1, A represents a rotational angle (a roll) having a z-axisof the camera coordinate system as a rotational axis, B represents arotational angle (a pitch) having an x-axis of the camera coordinatesystem as a rotational axis, and C represents a rotational angle (yaw)having a y-axis of the camera coordinate system as a rotational axis. Inaddition, t₁, t₂, and t₃ each represent a translation movement distancebetween the camera coordinate system and the global coordinate system.

FIG. 8A is a conceptual view illustrating light showing an X-rayirradiation region being radiated from the X-ray source, FIG. 8B is aview illustrating an example in which a light irradiation region isincluded in a camera image displayed on the display unit, and FIG. 9 isa view illustrating an example of displaying an X-ray irradiation windowbased on the light irradiation region. FIG. 10 is a view illustrating anX-ray irradiation window generated using coordinate information and anX-ray irradiation window generated through image processing.

Referring to FIG. 8A, a region matching the X-ray irradiation region Emay be irradiated with visible rays VL by a light source included in theX-ray source 110, e.g., a collimator lamp.

As illustrated in FIG. 8B, a light irradiation region L generated on asurface of the mounting unit 24 by the visible rays VL is also shown inthe camera image 152. The control unit 140 may extract a boundary of thelight irradiation region L from the camera image 152 through imageprocessing and may generate an X-ray irradiation window B2 based on theextracted boundary of the light irradiation region L as illustrated inFIG. 9. The generated X-ray irradiation window B2 may be displayed bybeing overlapped on the camera image 152. To distinguish the two X-rayirradiation windows B1 and B2 from each other, the X-ray irradiationwindow B1 generated by coordinate information may be referred to as afirst X-ray irradiation window B1, and the X-ray irradiation window B2generated through image processing may be referred to as a second X-rayirradiation window B2 in an embodiment to be described below.

The X-ray imaging apparatus 100 according to an embodiment undergoes acalibration process that matches the light irradiation region L formedby the collimator lamp and the actual X-ray irradiation region E anddetermines camera parameters such as the principal point, the focallength, and the installation angle, etc., of the capturing unit 120 sothat the X-ray irradiation windows B1 and B2 displayed on the displayunit 150 may accurately show the actual X-ray irradiation region E.

When an error does not occur in the calibration process, the X-rayirradiation window B1 generated using coordinate information and theX-ray irradiation window B2 generated through image processing matcheach other as illustrated in FIG. 10. Consequently, when the first X-rayirradiation window B1 and the second X-ray irradiation window B2 do notmatch each other, it may be determined that an error has occurred in thecalibration process described above. Thus, the control unit 140 performsa process of verifying whether an error has occurred in the calibrationprocess described above by performing a process of comparing the firstX-ray irradiation window B1 and the second X-ray irradiation window B2.

Since differences between positions, forms, and sizes of the X-rayirradiation windows B1 and B2 generated using the two methods describedabove imply that an error has occurred in the calibration process, thecontrol unit 140 may display, through the display unit 150, a message orthe like requesting that calibration be performed. In addition, the twoX-ray irradiation windows B1 and B2 not matching each other may beintuitively shown by displaying the first X-ray irradiation window B1and the second X-ray irradiation window B2 by overlapping the firstX-ray irradiation window B1 and the second X-ray irradiation window B2on the camera image 152. The user may check the message and perform thecalibration process described above again.

In addition, rather than displaying the message that requests thatcalibration be performed, the control unit 140 may calculate a degree ofdiscordance to calculate a calibration parameter for solving thediscordance when the X-ray irradiation windows generated using the twomethods described above do not match each other. The calibration may beautomatically performed based on the calculated calibration parameter,and the calibration parameter may be displayed on the display unit 150to guide the user to perform the calibration.

The control unit 140 may calculate a focal length and a principal pointof the capturing unit 120 required for solving the discordance based ondiscordance information, and may calculate variables required forconverting the global coordinate system into the camera coordinatesystem.

In addition, in the disclosed embodiment, an offset may occur due to adifference between the focal point of the capturing unit 120 and a focalpoint of the X-ray tube 111. The control unit 140 may use thediscordance information to calculate parameters required to compensatefor the offset. The control unit 140 may automatically performcalibration using the parameters calculated as above or may assist theuser to perform calibration by displaying the calculated parametersthrough the display unit 150.

Meanwhile, prior to X-ray imaging, the X-ray imaging apparatus 100according to an embodiment may perform a process of aligning the X-raysource 110 and the X-ray detector 200 with each other. The X-ray source110 and the X-ray detector 200 may be aligned with each other bymatching a center of the X-ray irradiation region and a center of theX-ray detector 200. Hereinafter, this will be described in detail withreference to FIGS. 11 to 15.

FIGS. 11 to 15 are views illustrating a method for aligning the X-raysource and an X-ray detector of the X-ray imaging apparatus according toan embodiment to each other.

As illustrated in FIG. 11, the control unit 140 generates an X-rayirradiation window B3 by the method using coordinate information or themethod of extracting a boundary of an X-ray irradiation region throughimage processing which are described above, and displays the generatedX-ray irradiation window B3 by overlapping the generated X-rayirradiation window B3 on the camera image 152 acquired by the capturingunit 120.

In addition, as illustrated in FIG. 12, the control unit 140 generates adetector boundary line B4 showing a boundary of the X-ray detector 200by the method using coordinate information or the method of extracting aboundary of the X-ray detector 200 shown in the camera image 152 throughimage processing which are described above, and displays the generateddetector boundary line B4 by overlapping the generated detector boundaryline B4 on the camera image 152 acquired by the capturing unit 120. Whenthe X-ray detector 200 is mounted inside the mounting unit 24 as in thisexample, the mounting unit 24 shown in the camera image 152 may be usedinstead of the X-ray detector 200.

The X-ray irradiation window B3 and the detector boundary line B4displayed by being overlapped on the camera image 152 may bedistinguished from each other by being displayed with different colors.In FIGS. 11 to 15, the X-ray irradiation window B3 is displayed with asolid line and the detector boundary line B4 is displayed with a dottedline.

In FIGS. 13 and 14, an example in which the detector boundary line B4and the X-ray irradiation window B3 are displayed together on thedisplay unit 150 is illustrated.

When intervals g between four vertices of the X-ray irradiation windowB3 and four vertices of the detector boundary line B4 respectivelycorresponding thereto are all the same as illustrated in FIG. 13, thecontrol unit 140 may determine that the X-ray detector 200 and the X-raysource 110 are aligned with each other.

Alternatively, when a center c1 of the X-ray irradiation window B3 and acenter c2 of the detector boundary line B4 match each other asillustrated in FIG. 14, the control unit 140 may determine that theX-ray detector 200 and the X-ray source 110 are aligned with each other.

When intervals g2, g3, g4, and g5 between the four vertices of the X-rayirradiation window B3 and the four vertices of the detector boundaryline B4 respectively corresponding thereto are different from eachother, or the center c1 of the X-ray irradiation window B3 and thecenter c2 of the detector boundary line B4 do not match each other asillustrated in FIG. 15, the control unit 140 may determine that theX-ray detector 200 and the X-ray source 110 are not aligned with eachother. In this case, the control unit 140 may calculate the intervalsg2, g3, g4, and g5 between the four vertices of the X-ray irradiationwindow B3 and the four vertices of the detector boundary line B4respectively corresponding thereto and calculate a moving distance and amoving direction of the X-ray source 110 or the X-ray detector 200 thatmatches the calculated intervals to each other.

The control unit 140 may match the intervals by moving the X-ray source110 or the X-ray detector 200 according to the moving distance and themoving direction of the X-ray source 110 or the X-ray detector 200calculated as above.

Alternatively, the control unit 140 may also guide the user to move theX-ray source 110 or the X-ray detector 200 by displaying the calculatedmoving distance and moving direction of the X-ray source 110 or theX-ray detector 200 through the display unit 150.

Alternatively, the control unit 140 may calculate an interval g1 betweenthe center c1 of the X-ray irradiation window and the center c2 of thedetector boundary line and, based on the calculated interval, maycalculate a moving direction and a moving distance of the X-ray source110 or the X-ray detector 200 that matches the center of the X-rayirradiation window and the center of the detector boundary line. Thecontrol unit 140 may match the center of the X-ray irradiation windowand the center of the detector boundary line by moving the X-ray source110 or the X-ray detector 200 according to the moving distance of theX-ray source 110 or the X-ray detector 200 calculated as above.

Alternatively, the control unit 140 may also guide the user to move theX-ray source 110 or the X-ray detector 200 by displaying the calculatedmoving direction or moving distance of the X-ray source 110 or the X-raydetector 200 through the display unit 150.

The moving distance and the moving direction of the X-ray source 110 orthe X-ray detector 200 may also be displayed as text, and the X-rayirradiation window B3, the detector boundary line B4, the intervalsbetween the vertices that do not match each other, and the intervalbetween the center c1 of the X-ray irradiation window and the center c2of the detector boundary line may also be displayed as images asillustrated in FIG. 15.

Meanwhile, when the X-ray source 110 and the X-ray detector 200 arealigned with each other, the user may input a predetermined operationcommand through the input unit 160 to adjust a position, size, or formof the X-ray irradiation window B3 displayed on the display unit 150.For example, the position, size, or form of the X-ray irradiation windowB3 may be adjusted by dragging a boundary of the X-ray irradiationwindow B3.

The X-ray irradiation window B3 may deviate from the boundary of theX-ray detector 200 while the user adjusts the X-ray irradiation windowB3.

FIG. 16 a view illustrating an example in which an X-ray irradiationwindow displayed on the display unit of the X-ray imaging apparatusaccording to an embodiment is deviated from a boundary of the X-raydetector.

As illustrated in FIG. 16, the X-ray irradiation window B3 displayed onthe display unit 150 may partially deviate from the boundary of theX-ray detector 200 shown in the camera image 152. Also in this example,the X-ray detector 200 is mounted inside the mounting unit 24, and onlythe mounting unit 24 is shown in the camera image 152. In this case,whether the X-ray irradiation window B3 is deviated from the boundary ofthe X-ray detector 200 may be determined based on whether the X-rayirradiation window B3 is deviated from the boundary of the mounting unit24.

Although a case in which the X-ray irradiation window B3 is partiallydeviated from the boundary of the X-ray detector 200 is illustrated inFIG. 16, the X-ray irradiation window B3 may also entirely deviate fromthe boundary of the X-ray detector 200.

When a region deviated from the boundary of the X-ray detector 200 isalso irradiated with X-rays, unnecessarily excessive X-ray exposure mayoccur. When the X-ray irradiation window B3 deviates from the boundaryof the X-ray detector 200 shown in the camera image 152, the controlunit 140 may inform the user by displaying a region B3-2 that isdeviated from the boundary of the X-ray detector 200 and a region B3-1that is present within the boundary of the X-ray detector 200 withdifferent colors as illustrated in FIG. 16 to prevent excessive X-rayexposure.

For example, the control unit 140 may display the region B3-1 that ispresent within the boundary of the X-ray detector 200 as green and theregion B3-2 that is deviated from the boundary of the X-ray detector 200as red to inform the user that the X-ray irradiation window B3 hasdeviated from the boundary of the X-ray detector 200. For reference, inthe example shown in FIG. 15, a boundary of the X-ray irradiation windowB3 that is present within the boundary of the X-ray detector 200 isdisplayed using a solid line, and a boundary of the X-ray irradiationwindow B3 that is deviated from the boundary of the X-ray detector 200is displayed using a dotted line to distinguish the two from each other.

Using different colors or a dotted line and a solid line to inform thatthe X-ray irradiation window has deviated from the boundary of the X-raydetector 200 is merely an example, and a sound or a vibration of theinput unit 160 may also be used. That is, the X-ray imaging apparatus100 may inform the user that the X-ray irradiation window displayed onthe display unit 150 has deviated from the boundary of the X-raydetector 200 using various methods based on a visual, aural, or tactilestimulation.

Meanwhile, to determine whether the X-ray irradiation window B3 hasdeviated from the boundary of the X-ray detector 200 shown in the cameraimage 152, the control unit 140 may compare a relation between positionsof the detector boundary line B4 and the X-ray irradiation window B3described above.

Since X-ray imaging is performed on the X-ray irradiation region E, theX-ray irradiation region may correspond to an X-ray imaging region. Whenthe X-ray imaging region is designated, the control unit 140 may controlthe collimator 113 to match the X-ray irradiation region E and thedesignated X-ray imaging region.

The X-ray imaging region may be directly designated by the user whenX-ray imaging is performed, but it may also be automatically designatedby being preset for each of a plurality of imaging protocols andselecting one of the imaging protocols when X-ray imaging is performedlater. Hereinafter, this will be described in detail with reference tothe drawings.

FIGS. 17 to 19 are views illustrating examples of presetting an imagingregion according to an imaging protocol, and FIG. 20 is a viewillustrating information stored in a storage unit

As illustrated in FIG. 17, an imaging region may be preset for each of aplurality of imaging protocols. The description related to the imagingprotocols is the same as described above.

To preset the imaging region for each of the plurality of imagingprotocols, the display unit 150 may display an imaging protocol settingwindow 154. The imaging protocol setting window 154 may include aprotocol list 154 c.

The user may select an imaging protocol whose imaging region is desiredto be set by the user from the protocol list 154 c using the input unit160.

To receive a setting of an imaging region, an object model 154 b havinga shape similar to that of an object, e.g., a target to be imaged, maybe displayed on the display unit 150, and the user may adjust a positionand size of an imaging window 154 a displayed on the object model 154 bto set an imaging region of the selected imaging protocol. In thisembodiment, the object is a human body, and the object model 154 b has ashape of a human body. The object model 154 b is only required to show arough silhouette of the object and does not have to show a detailedstructure of the object.

For example, a size or position of the imaging window 154 a may beadjusted by placing a cursor C on an edge or a vertex of the imagingwindow 154 a and selecting and dragging the imaging window 154 a.

Although the shape of the imaging window 154 a may be quadrilateral asin this example, the shape is not limited thereto, and the imagingwindow 154 a may also have shapes other than a quadrilateral shapeincluding a polygonal shape, a circular shape, and an elliptical shape.

In detailed examples of setting an imaging region for each of theplurality of imaging protocols, a region from a face to portions aboveknees of the object as illustrated in FIG. 18 may be set as a whole bodyAP, and a region from a neck to a waist of the object as illustrated inFIG. 19 may be set as a chest AP

As illustrated in FIG. 20, a set imaging region may be mapped to animaging protocol corresponding thereto and stored in a protocol database(DB), and the protocol DB may be stored in the storage unit 170.

In addition, an X-ray irradiation condition may also be mapped andstored for each of the plurality of imaging protocols together with theimaging region. In this case, the X-ray irradiation condition may bepreset for each of the plurality of imaging protocols or may be set bythe user.

When X-ray imaging is performed and one of the plurality of imagingprotocols is selected, the control unit 140 may search in the storageunit 170 for an imaging region mapped to the selected imaging protocoland perform X-ray imaging of the found imaging region.

In addition, when an X-ray irradiation condition is mapped and storedtogether with an imaging region, X-ray imaging may be performed byapplying the stored X-ray irradiation condition.

FIG. 21 is a view illustrating a process of extracting an imaging regioncorresponding to an imaging protocol from an image of an object, andFIG. 22 is a view illustrating a camera image in which the extractedimaging region is displayed.

The user may select an imaging protocol before X-ray imaging isperformed, and the capturing unit 120 may capture the camera image 152while the object is disposed in front of the X-ray detector 200.

The control unit 140 may search in the storage unit 170 for an imagingregion mapped to the selected imaging protocol and extract the imagingregion from the camera image 152.

The control unit 140 may extract the imaging region from the cameraimage 152 by applying image processing such as an object recognitionalgorithm thereto. For example, edge detection may be applied to thecamera image 152 to extract a silhouette or a form of the object anddetect a few features such as a length from head to toe (a height), awidth of a head or shoulders, and a length of a leg required torecognize the imaging region. In this example, when an approximateheight, width, and the like are recognized, required features may bedetected based on the approximate height, width, and the like evenwithout recognizing all detailed features of the object.

In another example, the form of an object may also be extracted byanalyzing a difference between a camera image with the object and acamera image without the object, and various image processingtechnologies such as object pattern detection and face recognition maybe applied to improve efficiency and accuracy of extracting an imagingregion.

When an imaging region is extracted from the camera image 152 by thecontrol unit 140, the control unit 140 may control the collimator 113such that the X-ray irradiation region E corresponds to the imagingregion. That is, the control unit 140 may control the collimator 113 sothat the imaging region is irradiated with X-rays. Here, when the X-raysource 110 or the X-ray detector 200 needs to be moved, the X-ray source110 or the X-ray detector 200 may be moved to a position correspondingto the imaging region. In addition, when the imaging region has a rangewhich cannot be covered by performing a single X-ray imaging, theimaging region may be divided and stitching imaging may be performed.

In addition, the display unit 150 may display the extracted imagingregion by overlapping the extracted imaging region 154 d on the cameraimage 152 as illustrated in FIG. 22 to provide the user with informationrelated to a region of the object 1 which will be captured.

FIG. 23 is a view illustrating an operation of presetting informationrelated to a size of the object, and FIG. 24 is a view illustratingpre-stored information related to the size of the object.

An X-ray irradiation condition in which an optimal X-ray image may beobtained may vary depending on a size of an object, and an allowablevalue of X-ray exposure may vary according to the size of the object.Consequently, the X-ray imaging apparatus 100 according to an embodimentmay preset an X-ray irradiation condition corresponding to each of aplurality of sizes of an object, and the user may directly classify thesizes of the objects.

Referring to an example shown in FIG. 23, the display unit 150 maydisplay an object size setting screen 156. Specifically, the displayunit 150 may display the object model 154 b and classify the sizes ofthe objects using the input unit 160. In a detailed example, a height, aheight of shoulders, and a length of legs may be designated and mappedas particular sizes. The height, the height of shoulders, and the lengthof legs may also be designated as particular values and may also bedesignated as a predetermined range.

To designate the height, the height of shoulders, and the length oflegs, the user may directly input values, may vertically andhorizontally drag an edge of the object model 154 b displayed on thedisplay unit 150, and may also vertically drag a line L_(H)corresponding to a height of a head, a line Ls corresponding to theheight of shoulders, and a line LL corresponding to the length of legs.

The sizes of the objects classified by the user may be stored in anobject size DB as illustrated in FIG. 24, and the object size DB may bestored in the storage unit 170.

Although sizes of objects may be classified as large, medium, small,child, baby, etc., an embodiment of the X-ray imaging apparatus 100 isnot limited thereto and may be further segmented or generalized.

FIG. 25 is a view illustrating a screen through which an X-rayirradiation condition may be set for each of a plurality of sizes of anobject.

Referring to FIG. 25, the settings window 151 through which an X-rayirradiation condition may be set may be displayed on the screen 150 a ofthe display unit 150. The user may set an X-ray irradiation conditionfor each of the plurality of sizes of an object.

The GUI through which an X-ray irradiation condition may be set for eachof the plurality of sizes of an object may be displayed on the settingswindow 151. For example, identification tags (Large, Medium, Small,Child, and Baby) capable of identifying pre-classified sizes of objectsmay be displayed at an upper portion of the settings window 151, and, amenu through which an X-ray irradiation condition for the selected sizeof an object may be set may be activated when the user manipulates theinput unit 160 to select one of the identification tags.

When the user moves the cursor C to select an identification tagcorresponding to a medium size (Medium), the object model 154 b in amedium size may be displayed at the right side of the settings window151 as a result of interoperation.

When an object size whose X-ray irradiation condition is desired to beset is selected, a GUI through which an X-ray irradiation condition forthe selected object size may be set may be activated.

When the GUI is activated, various types of graphical objects that maybe used to set the X-ray irradiation condition of the selected objectsize may be displayed. For example, the tube voltage setting button 151a for receiving a tube voltage setting, the tube current setting button151 b for receiving a tube current setting, and the exposure timesetting button 151 c for receiving an X-ray exposure time setting may bedisplayed in the settings window 151. The user may select each of thebuttons to set an X-ray irradiation condition to have a desired value.

In addition, the capture position setting button 151 d for receiving asetting related to whether X-ray imaging will be performed at the stand20 or at the table 10, the collimator setting button 151 f for receivinga setting related to a size of the collimator 113, the AEC selectionbutton 151 g for receiving a selection related to an AEC sensor, thesensitivity setting button 151 h for receiving a setting related tosensitivity, the button 151 i for receiving a setting related todensity, the grid selection button 151 j for receiving a selectionrelated to the grid, the filter selection button 151 k for receiving aselection related to a filter, the focal point selection button 151 rfor receiving a selection related to a size of a focal point, etc. maybe further displayed in the settings window 151.

The object size selection button 151 e may interoperate with a selectionof an identification tag. For example, when the use has selected theidentification tag corresponding to the medium size (Medium), an icon ofa medium-sized person included in the object size selection button 151 emay be highlighted and displayed.

When the setting an X-ray irradiation condition for each of theplurality of sizes of an object is finished, the user may select thepreset button 151 n to finish setting and may select the reset button151 m when attempting to initialize the settings.

The GUI illustrated in FIG. 25 is merely an example that may be appliedto the X-ray imaging apparatus 100, and it should be noted that the GUImay have a configuration different from that shown in FIG. 25.

Meanwhile, in addition to an object size in setting an X-ray irradiationcondition, an imaging protocol may also be taken into consideration. Inthis case, an X-ray irradiation condition may be set for each of theplurality of object sizes by segmenting each of the object sizesaccording to imaging protocols. For example, a large size X-rayirradiation condition may be set by segmenting a large size according toa whole body PA, a whole body AP, a whole body LAT, a chest PA, a chestAP, a chest LAT, a leg PA, a leg AP, and a leg LAT, and other remainingsizes may also be set likewise.

In addition, when stitching imaging needs to be performed due to afeature of an imaging protocol, the stitching region may also be dividedinto a plurality of regions based on the object model and an X-rayirradiation condition may be set for each of the divided regions.

The X-ray irradiation condition set for each of the plurality of sizesof objects may also be stored in the storage unit 170 or may also bestored in the object size DB together with the sizes of objects, forexample.

FIG. 26 is a view illustrating an operation of automatically determininga size of an object based on a camera image.

When the capturing unit 120 captures a camera image, the control unit140 may analyze the camera image to automatically determine a size of anobject.

For example, the control unit 140 may apply image processing such as anobject recognition algorithm to recognize a leg starting point, a toe, ashoulder, a head, etc. of the object 1 from the camera image 152 and maycalculate a leg length, a shoulder height, and a height in considerationof a recognition result, a source-to-image distance (ID), or asource-to-object distance (OD).

Alternatively, the control unit 140 may apply edge detection to thecamera image to extract a silhouette of the object and may also estimatean approximate size of the object in consideration of the size of thesilhouette of the object shown in the camera image, the SID, or the SOD.

For example, relations between the camera coordinate system based on thecapturing unit 120, the global coordinate system of the space in whichthe X-ray imaging apparatus 100 is disposed, and the two-dimensionalcoordinate system of the camera image may be pre-stored, and conversionsbetween the coordinate systems may be used to calculate the size of thesilhouette of the object displayed in the camera image in actual space.

The control unit 140 may search in the storage unit 170 for an X-rayirradiation condition corresponding to the estimated object size, andmay control the X-ray source 110 and the like according to the foundX-ray irradiation condition.

Meanwhile, when the control unit 140 determines a size of an object,X-ray irradiation conditions mapped as a default for the correspondingsize may be displayed on the settings window 151. The mapped X-rayirradiation conditions may be applied without change, or the user mayselect a button corresponding to each of the X-ray irradiationconditions and set each of the X-ray irradiation conditions again. Here,the user may set each of the X-ray irradiation conditions again withreference to default X-ray irradiation conditions displayed in thesettings window 151.

As mentioned above, when an X-ray imaging portion of the object islarger than the X-ray irradiation region E or a detection region inwhich the X-ray detector 200 may detect X-rays, the X-ray imagingportion may be divided into a plurality of regions, and X-ray imagingmay be separately performed for each of the plurality of dividedregions.

Meanwhile, obtaining a single entire X-ray image by dividing the X-rayimaging portion into a plurality of regions, imaging each of theplurality of divided regions and stitching the X-ray images for each ofthe plurality of divided regions may be referred to by various termssuch as panoramic imaging, stitching imaging, segmentation imaging, etc.For convenience of description, such imaging (panoramic imaging,stitching imaging, segmentation imaging, etc.) will be referred to asstitching imaging, in the embodiments which will be described. Also,each of the X-ray images for each of the divided regions will bereferred to as divided X-ray image and each of the X-ray imaging foreach of the divided regions will be referred to as divided imaging.Furthermore, one image generated by stitching together a plurality ofdivided X-ray images will be referred to as a stitched image.Hereinafter, an embodiment related to stitching imaging will bedescribed in detail with reference to the drawings.

FIG. 27 is a view illustrating an example of a stitched-together image,FIG. 28 is a view illustrating an example in which an imaging region isdivided to perform stitching imaging, and FIG. 29 is a view illustratingoverlapping regions between each of a plurality of divided regions.

As illustrated in FIG. 27, the X-ray imaging apparatus 100 may divide anX-ray imaging portion into a plurality of regions and may separatelyperform X-ray imaging for each of the plurality of divided regions.

The control unit 140 may stitch X-ray images of divided regions, i.e.,divided X-ray images X₁, X₂, and X₃, together to generate onestitched-together image X₁₂₃ showing a whole X-ray imaging portion. Inthis embodiment, an entire region in which stitching imaging is to beperformed will be referred to as a stitching region.

As described above, when the selected imaging protocol corresponds tothe stitching imaging, the work list 155 may be switched to the cameraimage 152 illustrated in FIG. 28. Also, an imaging region correspondingto the selected imaging protocol may be automatically designated as thestitching region. The control unit 140 may automatically divide thestitching region. For example, the control unit 140 may divide thestitching region into uniform sizes based on the smaller among height ofthe detection region and a maximum height of the X-ray irradiationregion.

In a detailed example, when a value obtained by dividing a height of astitching region S, i.e., a distance between a top line L_(T) showing apoint where the stitching region begins and a bottom line L_(B) showinga point where the stitching region ends, by a height of the region to bedetected by the X-ray detector 200 is an integer, the solution maybecome the number of divided regions, i.e., the number of divided X-rayimages, used in stitching imaging. On the other hand, when the value isnot an integer, the number of divided regions is larger than thesolution by one, and a height of each of the divided regions is smallerthan the height of the region to be detected by the X-ray detector 200.

For example, as illustrated in FIG. 28, when the stitching region S isdivided into three divided regions S₁, S₂, and S₃, three divided X-rayimages respectively corresponding to the divided regions may becaptured, and then the three divided X-ray images may be stitchedtogether to generate one stitched-together X-ray image.

Boundary portions between each of the divided X-ray images may bematched to stitch the divided X-ray images together, and X-rays may beradiated so that predetermined regions between the divided X-ray imagesoverlap each other for the matching. When designations of the dividedregions are completed, the control unit 140 may control the collimator113 to radiate X-rays to the divided regions such that X-rays isradiated to a range expanded from a divided region toward adjacentdivided regions by a predetermined size.

As an example illustrated in FIG. 29, X-rays may be radiated so that afirst-to-second overlapping region O₁₂ is disposed between the firstdivided region S₁ and the second divided region S₂, and asecond-to-third overlapping region O₂₃ is disposed between the seconddivided region S₂ and the third divided region S₃.

Since the overlapping regions O₁₂ and O₂₃ are redundantly irradiatedwith X-rays, when a radiosensitive portion such as a genital organ orthe heart is disposed in the overlapping regions, the control unit 140may move the overlapping regions to other portions to avoid redundantlyirradiating the radiosensitive portion with X-rays or may output awarning to the user.

Whether a radiosensitive portion is disposed in the overlapping regionsmay also be determined by applying image processing such as an objectrecognition algorithm to the camera image 152. For example, a portiondisposed at a central portion of a length from head to toe and fromwhich thighs originate may be determined as a portion at which a genitalorgan is disposed, and a portion spaced apart 20 cm or less downwardfrom armpit portions or shoulders may be determined as a portion atwhich the heart is disposed.

Information related to a radiosensitive portion, e.g., information on aposition or form thereof, may be pre-stored in the storage unit 170 ormay also be added or modified by the user.

When outputting a warning, the warning may be visually output throughthe display unit 150 or aurally output through a speaker provided in theX-ray imaging apparatus 100. When the warning is visually output, theoverlapping regions may be directly displayed on the display unit 150 asillustrated in FIG. 29, or text informing that the overlapping regionsare disposed at a radiosensitive portion may be displayed on the displayunit 150. Since the information simply needs to be conveyed, a method ofoutputting a warning is not limited.

The overlapping regions may be distorted in the stitched image and imagequality of the overlapping regions in the stitched image may bedegraded. Thus, the user may determine whether the overlapping portionsare important portions in an X-ray image that need to be protected fromdegradation of image quality based on the provided information relatedto the overlapping regions.

FIGS. 30 and 31 are views illustrating an operation in which overlappingregions are automatically adjusted.

With reference to FIG. 29 described above, a case in which thefirst-to-second overlapping region O₁₂ is disposed at a heart portionand the second-to-third overlapping region O₂₃ is disposed at a genitalregion portion is assumed.

As illustrated in FIG. 30, the control unit 140 may move a lowerboundary of the first divided region S₁ downward so that thefirst-to-second overlapping region O₁₂ is disposed below the heartportion ({circle around (1)}→{circle around (1)}′) and may move a lowerboundary of the second divided region S₂ downward so that thesecond-to-third overlapping region O₂₃ is disposed below the genitalorgan portion ({circle around (2)}+{circle around (2)}′).

Since a start point and an end point of the stitching region S areunchanged, the stitching region S does not change. Consequently, when asize of the first divided region S₁ exceeds a size of the region to bedetected by the X-ray detector 200 or the maximum height of X-rayirradiation region due to the movement of the lower boundary of thefirst divided region S₁, or when a size of the second divided region S₂exceeds the size of the region to be detected by the X-ray detector 200or the maximum X-ray irradiation region due to the movement of the lowerboundary of the second divided region S₂, the first divided region S₁ orthe second divided region S₂ may be further divided or the entirestitching region S may be further divided into smaller regions, and thenoverlapping regions may be re-controlled.

Alternatively, when a fact that overlapping regions are disposed atradiosensitive portions is output visually or aurally as describedabove, the overlapping region may also be adjusted by the user. In thiscase, radiosensitive portions 152 d may be displayed on the camera image152 as illustrated in FIG. 31 to guide the user to reset the overlappingregions by avoiding the radiosensitive portions. For example, the usermay move the overlapping regions displayed on the display unit 150 ormove boundary lines of a plurality of divided regions to reset theoverlapping regions.

FIGS. 32 and 33 are views related to a case in which a user directlydesignates a stitching region.

In the example described above, an imaging region that has been mappedto advance is designated as the stitching region S according to aselection of an imaging protocol. However, the stitching region may alsobe directly designated by the user.

As illustrated in FIGS. 32 and 33, the camera image 152 captured by thecapturing unit 120 may be displayed on the display unit 150. On thedisplay unit 150, the top line L_(T) showing the point where thestitching region begins and the bottom line L_(B) showing the pointwhere the stitching region ends may be displayed by being overlapped onthe camera image 152. By viewing the camera image 152, the user mayintuitively recognize the number of divided imaging operations necessaryfor acquiring a stitched image of the imaging region. In this aspect,the display unit 150 is configured to allow the user to intuitively andconveniently recognize the optimal number of divided imaging operations,thereby preventing excessive X-ray irradiation.

The top line L_(T) and the bottom line L_(B) may be initially displayedat any position on the camera image 152 or, when an imaging protocol isselected, may be displayed at positions corresponding to the selectedimaging protocol.

When the top line L_(T) and the bottom line L_(B) are displayed at anyposition on the camera image 152, the bottom line L_(B) may be disposedat a lower end portion of the camera image 152. Since an object's feetare disposed at the lower end portion of the camera image 152 regardlessof the size of the object, a work load of the user may be reduced whenthe bottom line L_(B) is disposed at the lower end portion of the cameraimage 152 since the user does not have to manipulate the input unit tomove the bottom line L_(B).

When the top line L_(T) and the bottom line L_(B) are displayed atpositions corresponding to an imaging protocol, the control unit 140 mayperform image processing such as applying an object recognitionalgorithm to the camera image 152 to recognize a portion correspondingto the imaging protocol.

Alternatively, only one of the top line L_(T) and the bottom line L_(B)may be displayed and the other one may be determined by designation ofthe number of divided imaging.

The user may manipulate the input unit 160 to adjust positions of thetop line L_(T) and the bottom line L_(B). To guide the manipulation bythe user, the display unit 150 may display the cursor C, and the cursorC may move on the screen displayed on the display unit 150 according tothe manipulation of the input unit 160 by the user.

In a case in which the input unit 160 is a mouse, a trackball, or akeyboard, when the user input control command for moving the top lineL_(T) and the bottom line L_(B) by manipulating the mouse, thetrackball, or the keyboard, the cursor C moves according to a directionand a movement amount corresponding to the manipulation. In a case inwhich the input unit 160 is a touch pad, the cursor C moves according toa direction in which the user's finger moves and a movement amount ofthe user's finger.

For example, the user may drag the top line L_(T) or the bottom lineL_(B) to move the top line L_(T) or the bottom line L_(B) to a desiredposition as illustrated in FIGS. 32 and 33. The top line L_(T) and thebottom line L_(B) may move in a vertical direction or in a longitudinaldirection of the object. As described above, the stitching region S maybe defined by the top line L_(T) and the bottom line L_(B). That is, aregion between the top line L_(T) and the bottom line L_(B) may be thestitching region S.

Alternatively, when the top line L_(T) and the bottom line L_(B) move toa position corresponding to a selected imaging protocol, the user mayalso re-designate the stitching region with reference to the movedpositions of the top line L_(T) and the bottom line L_(B).

When the stitching region S is designated, the control unit 140 mayautomatically divide the stitching region S. The description related tothe automatic division of the stitching region S is the same as in theexample described above.

The control unit 140 may perform real-time uniform division every timethe top line L_(T) and the bottom line L_(B) move and show the result.For example, when the stitching region S is divided into four regionsS₁, S₂, S₃, and S₄ as illustrated in FIG. 32, the regions may be dividedusing guide lines such as a dotted line, and the guide lines dividingthe regions may be numbered from 1 to 4 to provide information on thetotal number of divided regions and a number assigned to a correspondingregion.

The first guideline {circle around (1)} may be a bottom limit for amaximum region for which an X-ray image is to be acquired by performinga single X-ray imaging. The second guideline {circle around (2)} may bea bottom limit for a maximum region for which an X-ray image is to beacquired by performing an X-ray imaging twice. The third guideline{circle around (3)} may be a bottom limit for a maximum region for whichan X-ray image is to be acquired by performing an X-ray imaging threetimes. The fourth guideline {circle around (4)} may be a bottom limitfor a maximum region for which an X-ray image is to be acquired byperforming an X-ray imaging four times.

In addition, when the user has dragged the bottom line L_(B) toward thetop line L_(T) as illustrated in FIG. 33, the control unit 140 mayre-perform the real-time uniform division. When the stitching region Sis reduced and divided into three regions S₁, S₂, and S₃, the guidelines dividing the regions may be numbered from 1 to 3 to inform thatthe stitching region is divided into a total of three regions.

Also, to emphasize that the number of divided imaging has changed, thedisplay unit 150 may display the fourth guideline {circle around (4)},so as to be distinguished from the remaining first through thirdguidelines {circle around (1)} through {circle around (3)}. For example,the fourth guideline {circle around (3)} may be displayed as a dottedline, may be blurred or displayed in a different color. However,exemplary embodiments are not limited thereto, and the fourth guideline12-4 may be displayed in different ways to be distinguished from theremaining first through third guidelines {circle around (1)} through{circle around (3)}.

When the designation of the stitching region is completed, the user mayselect apply button 152 a and when the apply button 152 a is selected,the display unit 150 may display divided window W1, W2, W3 on the cameraimage 152 described below.

In addition, when the control command for moving the top line L_(T) orthe bottom line L_(B) is input again while the divided window isdisplayed, the present screen including the divided window may beswitched to the previous screen including guide lines so that thestitching region or the divided regions are re-designated.

Also in a case in which the user has directly designated the stitchingregion S, like the case described above, whether overlapping regions aredisposed at radiosensitive portions may be determined, and when it isfound that the overlapping regions are disposed at the radiosensitiveportions, a warning may be output or the overlapping regions may beautomatically controlled. Alternatively, the stitching region S may alsobe directly divided by the user. Also in this case, like the casedescribed above, whether overlapping regions are disposed atradiosensitive portions may be determined, and when it is found that theoverlapping regions are disposed at the radiosensitive portions, awarning may be output or the overlapping regions may be automaticallycontrolled. Also, radiosensitive portions may be displayed on the cameraimage 152 when the user inputs division of the stitching region S toguide the user's input so that the overlapping regions are not disposedat the corresponding radiosensitive portions.

Although the control unit 140 has been described in the embodiment aboveas dividing the stitching region S into uniform sizes, an embodiment ofthe X-ray imaging apparatus 100 is not limited thereto. The size of eachof the divided regions may also be adjusted to be different from eachother, and the size of each of the divided regions may also be directlyset by the user. The user may designate the start point and end point ofeach divided region. If it is desired to split the whole stitchingregion S into three divided regions, a start point and an end point of afirst divided region S₁, a start point and an end point of a seconddivided region S₂, and a start point and an end point of a third dividedregion S₃ may be designated.

If a designation of stitching imaging regions is performed by directlymoving a large X-ray source, which may make it difficult for a user toprecisely designate the stitching regions and may cause severe fatigueto the user.

According to the above embodiments, the X-ray imaging apparatus mayprecisely designate stitching regions and may reduce user fatigue.

In addition, repetitive irradiation of an important body part withX-rays may be prevented by adjusting overlapping regions automaticallyor manually.

FIGS. 34A to 36 are views illustrating a screen that allows a user toset a width of an X-ray irradiation region of each of the plurality ofdivided regions in the X-ray imaging apparatus according to anembodiment.

Conventionally, a width of a divided region is fixed according to anX-ray irradiation region determined by a collimator. However, since anarea occupied by an object is different in each of the divided regionseven with respect to a single object, an unnecessarily excessive X-rayexposure may occur when X-ray irradiation regions having the same widthare respectively applied to all of the divided regions.

Consequently, the X-ray imaging apparatus 100 according to an embodimentmay adjust a width of an X-ray irradiation region for each of theplurality of divided regions. Since the X-ray irradiation region isdetermined by a collimation region, adjusting the X-ray irradiationregion refers to adjusting the collimation region.

As illustrated in FIG. 34A, divided windows W1, W2, and W3 respectivelycorresponding to the plurality of divided regions may be displayed onthe camera image 152. The first divided window W1 corresponds to a firstdivided region, the second divided window W2 corresponds to a seconddivided region, and the third divided window W3 corresponds to a thirddivided region.

Alternatively, as illustrated in FIG. 34B, the display unit 150 maydisplay the divided windows W1, W2 and W3, adjacent ones of whichpartially overlap each other, over the camera image 152. The first andsecond divided windows W1 and W2 may overlap each other to representoverlapping region O₁₂ between the first divided region S₁ and thesecond divided region S₂, and the second and third divided windows W2and W3 may overlap each other to represent overlapping region O₂₃between the second divided region S₂ and the third divided region S₃.

Since the sizes of the divided windows respectively correspond to sizesof the divided regions, widths of the divided regions correspond to thewidth of the X-ray irradiation region E adjusted by the collimator 113.Heights of the divided regions may be determined according to thecontrol unit 140 or division performed by the user, and the collimator113 may be automatically adjusted according to the determined heights ofthe divided regions.

In this embodiment, the widths as well as the heights of the dividedregions are adjustable. The user may input a control command foradjusting the widths of the divided regions by horizontally draggingleft and right boundaries of the divided windows W1, W2, and W3.

For example, as illustrated in FIG. 35, the left boundary of the seconddivided window W2 may be dragged leftward and the right boundary thereofmay be dragged rightward to extend the width of the X-ray irradiationregion so that a whole body is included in the X-ray irradiation regionwith respect to a divided region corresponding to a body portion of theobject.

Alternatively, as illustrated in FIG. 36, the left boundary of the thirddivided window W3 may be dragged rightward and the right boundarythereof may be dragged leftward to reduce the width of the X-rayirradiation region so that a background without legs is excluded fromthe X-ray irradiation region with respect to a divided regioncorresponding to a leg portion of the object.

When the setting the width of the X-ray irradiation region for each ofthe plurality of divided regions is completed, the user may select anapply button 152 a, and the storage unit 170 may store information onthe set width of the X-ray irradiation region when the apply button 152a is selected.

The GUI through which an X-ray irradiation condition may be set for eachof the plurality of divided regions may be displayed on the settingswindow 151. For example, an identification tab 151 p through which adivided region may be identified may be displayed on the upper side ofthe settings window 151, and identification tags #1, #2, and #3respectively corresponding to the divided regions may be displayed onidentification tabs 151 p-1, 151 p-2, and 151 p-3, respectively. Whenthe user manipulates the input unit 160 and selects one of theidentification tabs, a GUI through which an X-ray irradiation conditionfor the selected divided region may be set may be activated.

The description related to various types of buttons displayed in anactivated GUI is the same in the example described above, and thus willbe omitted.

A size of a collimator, i.e., the size of the X-ray irradiation region,for each of the plurality of divided regions may also be adjusted usingthe collimator setting button 151 f displayed on the settings window151. Here, when the size of the collimator is adjusted by selecting thecollimator setting button 151 f, the camera image 152 displayed at theright side may interoperate therewith, and the widths of the dividedwindows W1, W2, and W3 may be jointly adjusted therewith.

Conversely, when the width of an X-ray irradiation region is adjusted byhorizontally dragging the boundaries of the divided windows W1, W2, andW3 as described above, the collimator setting button 151 f mayinteroperate therewith and change. For example, when the size of thecollimator with respect to the first divided region S₁ is reduced to14×17 by dragging the boundary of the divided window W1, the collimatorsetting button 151 f displayed on the settings window 151 may alsodisplay the size of 14×17.

Meanwhile, the width of the X-ray irradiation region may also beautomatically controlled by the control unit 140. In this case, thecontrol unit 140 may apply image processing such as edge detection tothe camera image to extract a silhouette of the object, and may controlthe width of the X-ray irradiation region based on a boundary betweenthe object silhouette and the background.

For example, the control unit 140 may prevent an unnecessarily excessiveX-ray exposure by reducing the width of the X-ray irradiation regionwhen the boundary between the object silhouette and the background isdisposed within the currently-shown X-ray irradiation region, and mayacquire required information by extending the width of the X-rayirradiation region when the boundary between the object silhouette andthe background is disposed outside the currently-shown X-ray irradiationregion.

When the setting the size of the X-ray irradiation region and the X-rayirradiation condition for all of the plurality of divided regions iscompleted, the user may select the exposure button 151 l to performX-ray imaging and may select the reset button 151 m when attempting toinitialize settings.

FIGS. 37 and 38 are views illustrating a screen that allows the user toselect an AEC sensor in the X-ray imaging apparatus according to anembodiment.

As described above, the plurality of AEC sensors 26 a, 26 b, and 26 cmay be used for automatically controlling a dose of X-rays. All or someof the plurality of AEC sensors 26 a, 26 b, and 26 c may be usedaccording to an X-ray imaging portion. Thus, a selection of an AECsensor may also be performed for each of the plurality of dividedregions.

As illustrated in FIG. 37, a plurality of graphical objects respectivelyshowing the plurality of AEC sensors 26 a, 26 b, and 26 c may bedisplayed within the divided windows W1, W2, and W3. The control unit140 may perform geometric registration of the camera image 152 bymatching each point in the camera image 152 with a position in theactual space. For example, the control unit 140 may use therelationships between camera coordinate system, global coordinate systemand image coordinate system.

The control unit 140 may acquire the positions of the AEC sensors 26 a,26 b, 26 c that correspond to the position of the X-ray detector 200 andcoordinate the AEC sensors 26 a, 26 b, 26 c with the camera image 152.The control unit 140 may perform image processing whereby the AECsensors 26 a, 26 b, 26 c are coordinated with the camera image 152 andthe graphical objects that correspond to the AEC sensors aresuperimposed onto the camera image 152.

For example, the graphical objects may include a plurality of AEC sensorbuttons 153 a-1, 153 b-1, and 153 c-1, a plurality of AEC sensor buttons153 a-2, 153 b-2, and 153 c-2, and a plurality of AEC sensor buttons 153a-3, 153 b-3, and 153 c-3 respectively corresponding to the plurality ofAEC sensors 26 a, 26 b, and 26 c. Each of the AEC sensor buttons may bedisplayed at a position corresponding to its AEC sensor.

The user may select an AEC sensor to be used for each of the pluralityof divided regions. When a button corresponding to an AEC sensor to beused among the plurality of AEC sensor buttons 153 a-1, 153 b-1, and 153c-1 in the first divided window W1 is selected, the AEC selection button151 g interoperates therewith, and the selection is also reflected anddisplayed on the AEC selection button 151 g of the settings window 151.

Conversely, when a selection of an AEC sensor is input using the AECselection button 151 g of the settings window 151 as illustrated in FIG.38, the plurality of AEC sensor buttons 153 a-2, 153 b-2, and 153 c-2interoperate therewith, and the selection is also reflected anddisplayed on the plurality of AEC sensor buttons 153 a-2, 153 b-2, and153 c-2.

When the selection of an AEC sensor is input, an AEC sensor buttoncorresponding to the selected AEC sensor may be highlighted by a changein color thereof, darkening or lightening an edge thereof, flickeringthe AEC sensor button etc. to reflect that the corresponding AEC sensorhas been selected. Alternatively, the selected AEC sensor andnon-selected AEC sensor may be distinguished from each other by solidline and dotted line. Alternatively, on/off may be displayed as text onthe AEC sensor buttons, and when an AEC sensor button with on isselected, the text may change from on to off. When an AEC sensor buttonwith off is selected, the text may change from off to on.

In addition, when a check box above the AEC selection button 151 g isselected, the plurality of AEC sensors may be turned on or off.

The selected AEC sensor may be turned on when an X-ray imaging isperformed, and the non-selected AEC sensor may be turned off when anX-ray imaging is performed. However, the reverse may be possible.

When the AEC sensor button displayed on the camera image 152 and the AECselection button 151 g displayed on the settings window 151 interoperatewith each other as described above, the user may more intuitivelyrecognize the position of the AEC sensor selected by himself or herself.

In addition, since the X-ray detector 200 is blocked by the object 1during X-ray imaging, the user is not able to directly recognize aposition of the AEC sensors. According to the exemplary embodimentdescribed above, the display unit 150 may display the AEC sensor buttonsover the camera image 152, thereby enabling the user to intuitively andconveniently recognize a relationship between positions of an actualobject and AEC sensors.

Furthermore, when the width of an X-ray irradiation region has beenadjusted as described above, an AEC sensor may be selected inconsideration of the adjusted width of the X-ray irradiation region. Forexample, when the width of the X-ray irradiation region is narrowed,only some of the AEC sensors may be selected.

Alternatively, an AEC sensor may also be automatically selected by thecontrol unit 140 based on a size of each of the plurality of dividedregions or a size of an X-ray irradiation region of each of the dividedregions. For example, the control unit 140 may exclude AEC sensors thatare disposed outside the X-ray irradiation region or are unnecessaryfrom being selected. Even when the control unit 140 has selected an AECsensor, the control unit 140 may display which AEC sensor has beenselected on the AEC selection button 151 g displayed on the settingswindow 151 and the AEC sensor button in the camera image 152. Forexample, the control unit 140 may detect a contour or edge of the object1 in the camera image 152 via image processing such as contour detectionor edge detection and turn off the AEC sensor outside the object 1.

If the AEC sensor outside the object 1 is not turned off, the AEC sensormay directly receive X-rays that have not passed through the object 1.This causes the amount of X-rays received by the AEC sensor to quicklyexceed a predetermined amount. In this case, the quality of an X-rayimage may be degraded due to the lack of X-ray dose irradiated on theobject 1.

Thus, the control unit 140 may prevent degradation in quality of anX-ray image by turning off an AEC sensor that is positioned outside theobject 1.

When the setting an X-ray irradiation region and an X-ray irradiationcondition for each of the plurality of divided regions is completed andthe exposure button 151 l is selected, the X-ray imaging apparatus 100may automatically control positions of the X-ray source 110 and theX-ray detector 200 to perform stitching imaging. Hereinafter, this willbe described with reference to FIGS. 39A to 39C.

FIGS. 39A to 39C are views related to a case in which stitching imagingis performed by controlling a tilt angle of the X-ray source in theX-ray imaging apparatus according to an embodiment. In this embodiment,a case in which capturing is performed by mounting the X-ray detector200 on the stand 20 is given as an example.

Before operating the X-ray imaging apparatus 100, calibration may beperformed to calculate a location relationship between a camera imageobtained through capturing unit 120 and an X-ray image.

For example, when the stitching region S is divided into the threeregions S₁, S₂, and S₃, the control unit 140 calculates a first locationor a first tilt angle at which the first divided region S₁ is irradiatedwith X-rays, a second location or a second tilt angle at which thesecond divided region S₂ is irradiated with X-rays, and a third locationor a third tilt angle at which the third divided region S₃ is irradiatedwith X-rays, based on the previous calibration result.

Prior to performing stitching imaging, it may be assumed that the X-raysource 110 has been moved to a position corresponding to the X-raydetector 200. For example, when both the stand 20 and the table 10 arepresent in an examination room and the user has selected the stand 20,the control unit 140 may move the X-ray source 110 to a positioncorresponding to the stand 20. The position of the X-ray source 110corresponding to the stand 20 may be pre-stored.

Alternatively, the X-ray source 110 may also be manually moved by theuser to the position corresponding to the stand 20.

A tilt angle of the X-ray source 110 may be adjusted to an anglecorresponding to the first divided region S₁ as illustrated in FIG. 39Ato capture the first divided X-ray image, the tilt angle of the X-raysource 110 may be adjusted to an angle corresponding to the seconddivided region S₂ as illustrated in FIG. 39B to capture the seconddivided X-ray image, and the tilt angle of the X-ray source 110 may beadjusted to an angle corresponding to the third divided region S₃ asillustrated in FIG. 39C to capture the third divided X-ray image. Here,a height of the X-ray source 110 from the ground may be fixed.

The control unit 140 may transmit a control signal to a motor thatadjusts the tilt angle of the X-ray source 110 to adjust the tilt angleof the X-ray source 110 to the angle corresponding to each of thedivided regions.

In addition, the control unit 140 may control the collimator 113 tocorrespond to sizes of the X-ray irradiation region of the first dividedregion, the second divided region, and the third divided region. Forexample, positions of the second blade 113 b and the fourth blade 113 dmay be fixed when the stitching region is divided into uniform sizes andheights of the divided regions are the same, and positions of the firstblade 113 a and the third blade 113 c may also be controlled when widthsof the divided regions or widths of the X-ray irradiation regions areset to be different from each other.

When a width of an X-ray irradiation region is extended more than adefault value, the first blade 113 a may be moved in a +x-axisdirection, and the third blade 113 c may be moved in a −x-axisdirection.

In addition, when X-ray irradiation conditions of the first dividedregion, the second divided region, and the third divided region are setto be different from each other, the X-ray source 110 or the X-raydetector 200 may be controlled to correspond to a set irradiationcondition when each of the divided regions is being captured.

In another example, the height of the X-ray source 110 may also beadjusted to a height corresponding to the first divided region S₁ tocapture the first divided X-ray image, adjusted to a heightcorresponding to the second divided region S₂ to capture the seconddivided X-ray image, and adjusted to a height corresponding to the thirddivided region S₃ to capture the third divided X-ray image. Here, thetilt angle of the X-ray source 110 may be fixed.

In yet another example, the height and the tilt angle of the X-raysource 110 may also be simultaneously adjusted.

In both of the examples, the X-ray detector 200 is moved to a positioncorresponding to each of the divided regions. To move the X-ray detector200, the control unit 140 may move the mounting unit 24 on which theX-ray detector 200 is mounted to a position corresponding to each of thedivided regions.

When each of the divided regions is designated, the control unit 140 maycalculate an actual position of the X-ray detector 200 to match thecenter of the designated divided region and the center of the X-raydetector 200. Also, as described regarding FIGS. 11-15, aligning theX-ray source 110 and the X-ray detector 200 may be performed.

Meanwhile, in a case of stitching imaging, since a plurality of X-rayimages which will be stitched together into one image are separatelycaptured, image quality of an X-ray image is degraded when an objectmoves between each of time points at which divided imaging is performed.Consequently, when performing stitching imaging, an orientation of theobject has to be controlled between each of the time points at whichdivided imaging is performed. Hereinafter, this will be described indetail.

FIG. 40 is a view illustrating an operation of determining a movement ofan object using a camera image, and FIGS. 41 and 42 are viewsillustrating controlling in a case in which re-imaging is performedafter stitching imaging is stopped while divided imaging is partiallycompleted.

Even while divided imaging is being performed, the capturing unit 120may capture a camera image, and the captured camera image may betransmitted to the control unit 140 in real-time. In addition, thecaptured camera image may be displayed on the display unit 150 inreal-time.

In addition, the captured camera image may be stored in the storage unit170. In this case, the stored camera image may be stored until anomission command is input by the user, and an oldest image may beautomatically omitted when a preset amount of time has passed or apreset storage capacity is exceeded.

As illustrated in FIG. 40, the control unit 140 may compare a cameraimage 152′ corresponding to a time point at which a previous dividedX-ray image is captured with the current camera image 152 to detect amovement of the object shown in the two images. In this example, theprevious divided X-ray image is the second divided X-ray image, and theimage to be currently captured is the third divided X-ray image.

For example, the movement of the object may be detected by analyzing adifference d between the two images. The movement may be detected bycomparing an orientation of the object shown in the camera image whenthe second divided imaging is performed and an orientation of the objectshown in the current camera image.

When the detected movement has a value equal to or greater than a presetreference value, it may be determined that matching the first dividedX-ray image and the second divided X-ray image is impossible even whenthe third divided X-ray image is captured. Consequently, the controlunit 140 may visually or aurally warn of a situation in which matchingis impossible or automatically stop stitching imaging.

When the movement of the object has a value equal to or greater than thereference value as described above or a condition of the object isunstable or critical, imaging may be stopped while divided imaging ispartially completed.

For example, as illustrated in FIG. 41, after the first divided X-rayimage X₁ and the second divided X-ray image X₂ are captured, imaging maybe stopped before X-ray imaging of the third divided region S₃ isperformed. Although it is illustrated in this example that the firstdivided X-ray image X₁ and the second divided X-ray image X₂ arestitched together in advance and a stitched-together image X₁₂ of thefirst divided region and the second divided region is generated, thefirst divided X-ray image X₁, the second divided X-ray image X₂, and thethird divided X-ray image X₃ may also be stitched together at one timeafter the third divided X-ray image is acquired.

The first divided X-ray image X₁ and the second divided X-ray image X₂and the camera images captured during the first divided imaging or thesecond divided imaging may be stored together in the storage unit 170.Information on divided regions for stitching imaging may also be storedin the camera images. The identification tags may be stored together sothat the stored divided X-ray images or camera images may be loaded whenstitching imaging is resumed later, and the identification tags mayinclude information capable of classifying studies. The informationcapable of classifying studies may be one of an object name, adate/capturing time, an imaging protocol, and a combination thereof, orinformation set by the user regardless of the above.

When the same stitching imaging is resumed after the stitching imagingis stopped, the control unit 140 may search for and load a camera imagestored in the storage unit 170. For this, the user may input anidentification tag corresponding to stitching imaging to be currentlyresumed.

As illustrated in FIG. 42, the current camera image may be displayed onthe display unit 150, and a camera image loaded from the storage unit170, i.e., a camera image captured at a time point at which previousdivided imaging was performed, may be displayed by being overlapped onthe current camera image.

According to this example, the camera image 152′ captured during thesecond divided imaging may be displayed by being overlapped on thecurrent camera image, and the user may guide the orientation of theobject with reference to the overlapped camera images. Since the twoimages overlap each other, the user may accurately recognize adifference between orientations of the object shown in the two imagesand guide the current orientation of the object to match the orientationof the object during the second divided imaging.

When the orientation of the object matches the orientation of the objectduring previous divided imaging according to the user's guide, i.e.,when the current orientation of the object matches the orientation ofthe object during the second divided imaging, third divided imaging maybe performed. Here, whether the orientations of the object match may bedetermined with the naked eye by the user or may also be determined bythe control unit 140 according to the standard for detecting a movementdescribed above. For example, it may be determined that the orientationsmatch when an object silhouette in the previous camera image 152′ and anobject silhouette in the current camera image 152 match. In addition,the fact that the orientation during the previous divided imagingmatches the current orientation may be output visually or aurally suchthat the user may select the exposure button, or the divided imaging mayalso be automatically performed by the control unit 140.

The third divided X-ray image X₃ may be acquired when the third dividedimaging is performed. The control unit 140 may load the first dividedX-ray image X₁ and the second divided X-ray image X₂ or astitched-together image X₁₂ in which the two X-ray images are stitchedtogether stored in the storage unit 170 to perform stitching with thethird divided X-ray image X₃ to generate the stitched-together imageX₁₂₃ of the entire stitching region S.

Alternatively, even in a case other than the case in which stitchingimaging is stopped and resumed, the orientation of the object may beguided by overlapping the camera image acquired during previous dividedimaging on the current camera image.

For example, when it is impossible to perform a subsequent dividedimaging due to a large movement amount of a patient as described above,an orientation of an object may be guided by overlapping the cameraimage 152′ acquired during a previous divided imaging on the currentcamera image 152.

Hereinafter, a method for controlling an X-ray imaging apparatusaccording to an embodiment will be described.

The X-ray imaging apparatus 100 described above may be used in themethod for controlling an X-ray imaging apparatus according to anembodiment. Consequently, the descriptions given above may also beidentically applied to the method for controlling an X-ray imagingapparatus.

FIG. 43 is a flowchart illustrating an example of a method for verifyingan X-ray irradiation region in a method for controlling an X-ray imagingapparatus according to an embodiment.

Referring to FIG. 43, the control unit 140 uses coordinate informationof the X-ray imaging apparatus 100 to generate an X-ray irradiationwindow displayed on the display unit 150 (410). The control unit 140 mayuse pre-stored coordinate information of the X-ray imaging apparatus 100to acquire information on a position and size of the X-ray irradiationwindow.

The control unit 140 may include pre-stored pieces of information on adistance between the X-ray source 110 and the X-ray detector 200, a formand an area of the slot R to be irradiated with X-rays formed by thecollimator 113, a distance from the X-ray tube 111 to the slot R, etc.,or may calculate the above pieces of information from pre-storedinformation.

The control unit 140 may use the above pieces of information tocalculate three-dimensional coordinates of the X-ray irradiation regionE formed at the X-ray detector 200. The three-dimensional coordinates ofthe X-ray irradiation region E calculated by the control unit 140corresponds to coordinates on a global coordinate system of a space inwhich the X-ray imaging apparatus 100 is disposed.

Since the X-ray irradiation window B1 is displayed by being overlappedon a camera image acquired by the capturing unit 120 and the X-rayirradiation window B1 displayed by being overlapped on the camera imageis based on a two-dimensional coordinate system, the control unit 140has to convert the calculated information on the three-dimensionalcoordinates of the X-ray irradiation region E into coordinates based ona two-dimensional image coordinate system.

In addition, since the coordinates of the capturing unit 120 and theglobal coordinate system are different, the global coordinate system hasto be converted into a camera coordinate system to convert theinformation on the three-dimensional coordinates of the X-rayirradiation region E into coordinates based on the two-dimensional imagecoordinate system. That is, the global coordinate system has to beconverted into the camera coordinate system, and the information on thethree-dimensional coordinates converted into coordinates based on thecamera coordinate system has to be converted into coordinates based onthe two-dimensional image coordinate system.

The control unit 140 may use the two-dimensional coordinates obtained asabove to display the X-ray irradiation window B1 by overlapping theX-ray irradiation window B1 on the camera image on the display unit 150.

In addition, the control unit 140 performs image processing of an imageof the light irradiation region L of the collimator 113 acquired by thecapturing unit 120 to generate the X-ray irradiation window B2 displayedon the display unit 150 (411).

As described above, the X-ray irradiation window B1 may be displayed onthe display unit 150 using the coordinate information, or the X-rayirradiation window B2 may be displayed by extracting a boundary of thelight irradiation region L shown in the camera image acquired by thecapturing unit 120 through image processing.

When the X-ray irradiation window B1 generated using the coordinateinformation and the X-ray irradiation window B2 generated through imageprocessing do not match (No to 412), the control unit 140 performscalibration (413).

The X-ray imaging apparatus 100 according to the disclosed embodimentundergoes a calibration process that matches the light irradiationregion and the actual X-ray irradiation region by adjusting a collimatorlamp and a reflector and determines camera parameters such as aprincipal point, a focal length, an installation angle, etc. of thecapturing unit 120 such that an X-ray irradiation window displayed onthe display unit 150 may accurately show the actual X-ray irradiationregion E.

When an error does not occur in the calibration process, the X-rayirradiation window generated using coordinate information and the X-rayirradiation window generated through image processing match each other.Consequently, when the X-ray irradiation window and the X-rayirradiation window do not match each other, an error may be determinedas having occurred in the calibration process described above.

Consequently, the control unit 140 performs a process of verifyingwhether an error has occurred in the calibration process described aboveby performing a process of comparing the X-ray irradiation window B1generated using coordinate information and the X-ray irradiation windowB2 generated through image processing with each other to find outwhether the two match.

Since discordance between the X-ray irradiation windows generated usingthe two methods described above implies that an error has occurred inthe calibration process, the control unit 140 may display a message orthe like requesting that calibration be performed through the displayunit 150. The user may check the message and re-perform the calibrationprocess described above.

In addition, rather than displaying the message that requests thatcalibration be performed, the control unit 140 may calculate a degree ofdiscordance to, calculate a camera parameter for solving the discordancewhen the X-ray irradiation windows generated using the two methodsdescribed above do not match each other. The control unit 140 maycalculate a focal length and a principal point of the capturing unit 120required for solving the discordance based on discordance informationand may calculate variables required for converting the globalcoordinate system into the camera coordinate system. In addition, in thedisclosed embodiment, an offset may occur due to a difference betweenthe focal point of the capturing unit 120 and a focal point of the X-raytube 111. The control unit 140 may use the discordance information tocalculate parameters required to compensate for the offset. The controlunit 140 may automatically perform calibration using the parameterscalculated as above or assist the user to perform calibration bydisplaying the calculated parameters through the display unit 150.

FIG. 44 is a flowchart illustrating an example of a method for aligningan X-ray source and an X-ray detector to each other in the method forcontrolling an X-ray imaging apparatus according to an embodiment.

As illustrated in FIG. 44, the control unit 140 displays a boundary ofthe X-ray detector 200 and an X-ray irradiation region on the displayunit 150 (421).

The control unit 140 may generate the X-ray irradiation window B3 by themethod using coordinate information or the method for extracting aboundary of an X-ray irradiation region through image processingdescribed above to display the X-ray irradiation region, and may displaythe generated X-ray irradiation window B3 by overlapping the generatedX-ray irradiation window B3 on the camera image 152.

In addition, the control unit 140 may generate the detector boundaryline B4 showing the boundary of the X-ray detector 200 by the methodusing coordinate information or the method for extracting the boundaryof the X-ray detector 200 through image processing described above todisplay the boundary of the X-ray detector 200, and may display thegenerated detector boundary line B4 by overlapping the generateddetector boundary line B4 on the camera image 152.

The X-ray irradiation window B3 and the detector boundary line B4displayed by being overlapped on the camera image 152 may bedistinguished from each other by using different colors or by using adotted line and a solid line.

The control unit 140 determines whether a center of the detectorboundary line B4 and a center of the X-ray irradiation window B3 match(422), and when the two do not match (No to 422), calculates a movingdistance of the X-ray source 110 and the X-ray detector 200 based on adegree of discordance between the center of the detector boundary lineB4 and the center of the X-ray irradiation window B3 (423). In addition,the moving distances may be calculated together, and the control unit140 moves and aligns the X-ray source 110 and the X-ray detector 200according to the calculated moving distances and moving direction (424).

When intervals between four vertices forming the X-ray irradiationwindow B3 and four vertices forming the detector boundary line B4entirely match each other, the control unit 140 may determine that theX-ray detector 200 and the X-ray source 110 are aligned with each other.

Alternatively, when the center of the detector boundary line B4 and thecenter of the X-ray irradiation window B3 match (Yes to 422), thecontrol unit 140 may determine that the X-ray detector 200 and the X-raysource 110 are aligned with each other.

When the intervals between the four vertices forming the X-rayirradiation window B3 and the four vertices forming the detectorboundary line B4 are different from each other or the center of theX-ray irradiation window B3 and the center of the detector boundary lineB4 do not match, the control unit 140 may determine that the X-raydetector 200 and the X-ray source 110 are not aligned with each other.In this case, the control unit 140 may calculate the intervals g2, g3,g4, and g5 between the four vertices of the X-ray irradiation window B3and the four vertices of the detector boundary line respectivelycorresponding thereto and calculate a moving distance and a movingdirection of the X-ray source 110 or the X-ray detector 200 that maymatch the calculated intervals to each other. The control unit 140 maymatch the intervals by moving the X-ray source 110 or the X-ray detector200 based on the moving distance and the moving direction of the X-raysource 110 or the X-ray detector 200 calculated as above. Alternatively,the control unit 140 may also guide the user to move the X-ray source110 or the X-ray detector 200 by displaying the calculated movingdistance and moving direction of the X-ray source 110 or the X-raydetector 200 through the display unit 150.

Alternatively, the control unit 140 may calculate the interval g1between the center of the X-ray irradiation window B3 and the center ofthe detector boundary line B4 and, may calculate the moving direction orthe moving distance of the X-ray source 110 or the X-ray detector 200that matches the center of the X-ray irradiation window B3 and thecenter of the detector boundary line B4 based on the calculatedinterval. The control unit 140 may match the center of the X-rayirradiation window B3 and the center of the detector boundary line B4 bymoving the X-ray source 110 or the X-ray detector 200 based on themoving direction and the moving distance of the X-ray source 110 or theX-ray detector 200 calculated as above. By this, the control unit 140may match centers of the actual X-ray irradiation region and the X-raydetector 200. Alternatively, the control unit 140 may also guide theuser to move the X-ray source 110 or the X-ray detector 200 bydisplaying the calculated moving direction and moving distance of theX-ray source 110 or the X-ray detector 200 through the display unit 150.

When the center of the detector boundary line B4 and the center of theX-ray irradiation window B3 match, the control unit 140 receives anadjustment command for adjusting an X-ray irradiation region (425), andwhen a portion deviated from the detector boundary line B4 is presentwithin the X-ray irradiation window B3 displayed on the display unit 150(Yes to 426), the control unit 140 displays the portion deviated fromthe detector boundary line B4 (427).

When the X-ray source 110 and the X-ray detector 200 are aligned witheach other, the user may input a predetermined operation command throughthe input unit 160 to adjust a position, size, or form of the X-rayirradiation window B3.

The X-ray irradiation window B3 may deviate from the detector boundaryline B4 while the user adjusts the X-ray irradiation window B3. When aregion deviated from the boundary of the X-ray detector 200 is alsoirradiated with X-rays, unnecessarily excessive X-ray exposure mayoccur. Consequently, when the X-ray irradiation window B3 deviates fromthe detector boundary line B4, the control unit 140 may inform the userby displaying the region B3-2 that is deviated from the detectorboundary line B4 and the region B3-1 that is present within the detectorboundary line B4 with different colors to prevent excessive X-rayexposure. For example, the control unit 140 may display the region thatis present within the detector boundary line B4 as green and the regionthat is deviated from the detector boundary line B4 as red to inform theuser that the X-ray irradiation window has deviated from the boundary ofthe X-ray detector 200. Alternatively, notification regarding a regiondeviated from the boundary of the X-ray detector 200 may also beprovided using a dotted line and a solid line instead of using differentcolors.

Informing that the X-ray irradiation window has deviated from theboundary of the X-ray detector 200 using different colors or using adotted line and a solid line is merely an example, and a sound or avibration of the input unit 160 may also be used. That is, the X-rayimaging apparatus 100 according to the disclosed embodiment may informthe user that the X-ray irradiation window displayed on the display unit150 has deviated from the boundary of the X-ray detector 200 usingvarious methods based on a visual, aural, or tactile stimulation.

FIG. 45 is a flowchart related to a method for setting an imagingprotocol in the method for controlling an X-ray imaging apparatusaccording to an embodiment.

Referring to FIG. 45, an imaging region is set for each of a pluralityof imaging protocols (430). The imaging region may be set according tothe user's input. For this, the display unit 150 may display the imagingprotocol setting window 154. The imaging protocol setting window 154 mayinclude the protocol list 154 c.

The user may select an imaging protocol whose imaging region is desiredto be set by the user from the protocol list 154 c using the input unit160. The object model 154 b having a shape similar to that of an objectmay be displayed on the display unit 150 to receive a setting of animaging region, and the user may adjust a position and size of theimaging window 154 a displayed on the object model 154 b to set animaging region of the selected imaging protocol. An imaging region setfor each of the imaging protocols is stored in the storage unit 170.

Then, prior to performing X-ray imaging, the capturing unit 120 is usedto capture a camera image (431). A time difference may exist betweenX-ray imaging and the imaging region for each of the imaging protocols.

An imaging protocol is selected (432). The imaging protocol may beselected by the user's input.

An imaging region mapped to the selected imaging protocol is searchedfor (433). The imaging region may be searched for by the control unit140. For example, when the selected imaging protocol is a chest PA, animaging region mapped and stored in the chest PA is searched for.

The imaging region is extracted from a camera image (434). For example,the control unit 140 may extract an imaging region from the camera image152 by applying image processing such as an object recognitionalgorithm. For example, edge detection may be applied to the cameraimage 152 to extract a silhouette or a form of the object and detect afew features such as a length from head to toe (a height), a width ofthe head or shoulders, and a length of a leg required to recognize theimaging region.

The imaging region is irradiated with X-rays to perform X-ray imaging(435). When the imaging region is extracted from the camera image 152 bythe control unit 140, the control unit 140 may control the collimator113 to correspond the X-ray irradiation region E to the imaging region.When the X-ray source 110 or the X-ray detector 200 should be moved, theX-ray source 110 or the X-ray detector 200 may be moved to a positioncorresponding to the imaging region. In addition, when the imagingregion has a range which cannot be covered by performing a single X-rayimaging, the imaging region may be divided and stitching imaging may beperformed.

FIG. 46 is a flowchart related to a method for determining whetherdivided imaging has stopped according to a movement of an object in themethod for controlling an X-ray imaging apparatus according to anembodiment. In this example, stitching imaging is performed, and astitching region is divided into a first divided region, a seconddivided region, and a third divided region.

Referring to FIG. 46, the capturing unit 120 is used to capture a cameraimage (440). The capturing unit 120 may capture a video in real time orcapture a camera image until X-ray imaging is finished.

First divided imaging is performed (441). For this, a position or tiltangle of the X-ray source 110 may be controlled to be a position or anangle corresponding to the first divided region, and a position of theX-ray detector 200 may be controlled to be a position corresponding tothe first divided region.

A movement of the object is detected (442). Specifically, the controlunit 140 may compare an orientation of the object shown in the currentcamera image with an orientation of the object shown in the camera imageduring the first divided imaging to detect the movement.

When the detected movement has a value equal to or greater than a presetreference value (Yes to 443), matching the first divided X-ray image andthe second divided X-ray image may be determined to be impossible evenwhen divided imaging is performed and imaging may be stopped.

When the detected movement does not have a value equal to or greaterthan the preset reference value (No to 443), second divided imaging isperformed (444).

A movement of the object is detected (445). The control unit 140 maycompare an orientation of the object shown in the current camera imagewith an orientation of the object shown in the camera image during thesecond divided imaging to detect the movement.

When the detected movement has a value equal to or greater than thepreset reference value (Yes to 446), matching the second divided X-rayimage and the third divided X-ray image may be determined to beimpossible even when divided imaging is performed and imaging may bestopped.

When the detected movement does not have a value equal to or greaterthan the preset reference value (No to 446), third divided imaging isperformed (447).

Alternatively, a warning may be output to the user without stopping thecapturing to guide the user to guide the orientation of the object.

When the third divided imaging is finished, the first divided X-rayimage, the second divided X-ray image, and the third divided X-ray imagemay be stitched together to generate one stitched-together image.

FIG. 47 is a flowchart related to a case of resuming stitching imagingin the method for controlling an X-ray imaging apparatus according to anembodiment.

As described above, imaging may be stopped while divided imaging ispartially completed when the movement of the object has a value equal toor greater than a reference value, or a condition of the object isunstable or critical.

Divided X-ray images that have been already captured as well as cameraimages captured while divided imaging is performed may be stored in thestorage unit 170 when stitching imaging is stopped. Information ondivided regions for stitching imaging may also be stored in the cameraimages.

In addition, when stitching imaging is resumed afterwards (450), thecontrol unit 140 may search for and load a camera image mapped andstored for the resumed stitching imaging in the storage unit 170.

The display unit 150 may display a previous camera image by allowing theprevious camera image to overlap the current camera image (451). Theuser may guide the orientation of the object with reference to theoverlapped camera images. Since the two images overlap each other, theuser may accurately recognize the difference between orientations of theobject shown in the two images and guide the current orientation of theobject to match the orientation of the object during the second dividedimaging.

FIG. 48 is a flowchart related to a method for controlling anoverlapping region in the method for controlling an X-ray imagingapparatus according to an embodiment.

Referring to FIG. 48, a stitching region in which stitching imaging willbe performed is designated (460). The stitching region may be designatedby a direct input of a user or may also be automatically designated byselecting an imaging protocol. That is, an imaging region correspondingto the selected imaging protocol may be designated as the stitchingregion.

The stitching region is divided (461). For example, the stitching regionmay be divided into uniform sizes in consideration of a size of thestitching region and a size of the region to be detected by the X-raydetector 200.

Whether an overlapping region is disposed at a radiosensitive portion isdetermined (462). Whether the overlapping region is disposed at aradiosensitive portion may also be determined by applying an objectrecognition algorithm. For example, a portion disposed at a centralportion of a length from head to toe and from which thighs originate maybe determined as a portion at which a genital organ is disposed, and aportion spaced apart 20 cm or less downward from armpit portions orshoulders may be determined as a portion at which the heart is disposed.Information related to a radiosensitive portion may be pre-stored in thestorage unit 170 or may also be added or modified by the user.

When the overlapping region is disposed at a radiosensitive portion (Yesto 462), the overlapping region may be adjusted (463). The overlappingregion may be adjusted automatically by the control unit 140 oraccording to the user's input. In the former case, the control unit 140may adjust a boundary of a corresponding divided region so that theoverlapping region may avoid the radiosensitive portion. In the lattercase, a position of the radiosensitive portion may be displayed on thedisplay unit 150 to guide the user's input.

FIG. 49 is a flowchart related to a method for presetting a size of anobject in the method for controlling an X-ray imaging apparatusaccording to an embodiment.

Referring to FIG. 49, a size of an object is set and stored (470). Forexample, the display unit 150 may display the object size setting screen156. Specifically, the display unit 150 may display the object model 154b, and the user may use to input unit 160 to classify sizes of anobject. In a detailed example, a height, a height of shoulders, and alength of legs may be designated and mapped as particular sizes. Theheight, the height of shoulders, and the length of legs may also bedesignated as particular values and may also be designated as apredetermined range. The sizes of the object classified by the user maybe stored in an object size DB, and the object size DB may be stored inthe storage unit 170. Although sizes of an object may be classified aslarge, medium, small, child, baby, etc., an embodiment of the X-rayimaging apparatus 100 is not limited thereto and the sizes may befurther segmented or generalized.

An X-ray irradiation condition is set for each of a plurality of objectsizes and stored (471). For example, the settings window 151 throughwhich an X-ray irradiation condition may be set may be displayed on thedisplay unit 150. The user may set the X-ray irradiation condition foreach of the object sizes. The X-ray irradiation condition that can beset may include a tube voltage, a tube current, and an exposure time,and may also include a position at which X-ray imaging is performed (astand and a table for performing X-ray imaging), a collimator size, aposition of an AEC sensor, sensitivity, density, and a grid. The X-rayirradiation conditions set for each of the object sizes may be stored inthe storage unit 170.

After the object sizes and the X-ray irradiation conditions are set, thecapturing unit 120 may capture a camera image when the object isdisposed in front of the X-ray detector 200 for X-ray imaging. Inaddition, the control unit 140 analyzes the camera image to determine asize of the object (472). For example, the control unit 140 may applyedge detection to the camera image to extract a silhouette of the objectand may also estimate an approximate size of the object in considerationof the size of the silhouette of the object shown in the camera image,the SID, or the SOD.

An X-ray irradiation condition corresponding to the object size issearched for (473). Then, an X-ray source is controlled according to afound X-ray irradiation condition (474). In addition, when the X-rayirradiation condition stored corresponding to the object size includes acondition related to the X-ray detector 200, the X-ray detector 200 mayof course be further controlled.

Some of the operations of the X-ray imaging apparatus and the method forcontrolling the same described above may be stored as programs in acomputer-readable recording medium. The recording medium may be amagnetic recording medium such as a read-only memory (ROM), a floppydisk, and a hard disk, or an optical recording medium such as a compactdisk (CD)-ROM and a digital versatile disk (DVD). However, types of therecording medium are not limited to the examples above.

The recording medium may be included in a server that providesapplications or programs, and a work station, a sub-display device, or amobile device may access the server via a communication protocol such asthe Internet to download a corresponding program.

For example, when the display unit 150 and the input unit 160 describedabove are included in a mobile device, the screen described above may bedisplayed on the display unit 150 after the mobile device downloads,installs, and executes a program.

Steps of executing some of the operations of the control unit 140described above may be included in the program. In this case, the mobiledevice may generate a control command and transmit the control commandto the X-ray imaging apparatus 100.

Alternatively, the mobile device may transmit information related to acontrol command input by the user to the X-ray imaging apparatus 100,and the control unit 140 may control the X-ray imaging apparatus 100according to the control command input by the user.

According to an X-ray imaging apparatus and a method for controlling thesame according to an aspect, a camera image can be used to set varioustypes of parameters related to X-ray imaging including an X-rayirradiation region and X-ray imaging can be automatically controlled.

The descriptions above are merely illustrative descriptions of thetechnical spirit of the present disclosure, and those of ordinary skillin the art to which the present disclosure pertains should be able tomake various modifications, changes, and substitutions within a scopethat does not depart from essential features of the present disclosure.Consequently, the embodiments disclosed above and the accompanyingdrawings are for describing, instead of limiting, the technical spiritof the present disclosure, and the scope of the technical spirit is notlimited by the embodiments and the accompanying drawings. The scopeshould be construed by the claims below, and all technical spiritswithin the scope equivalent to the claims should be construed asbelonging to the scope of the present disclosure.

What is claimed is:
 1. An imaging apparatus, comprising: a cameraconfigured to capture a camera image of a target disposed on anexamination table configured to be movable; an X-ray source configuredto generate and radiate X-rays; a memory configured to store imagingprotocols; a display; and a controller configured to: receiveinformation regarding a selection of an imaging protocol among thestored imaging protocols, identify a position of an imaging region ofthe target disposed on the examination table based on the camera image,the imaging region corresponding to the selection of the imagingprotocol and the camera image being acquired with the examination tableat a first distance from the X-ray source, control the display todisplay the camera image of the target and an indicator indicating theimaging region on the camera image based on the identified position, andcontrol the X-ray source to generate and radiate the X-rays toward thetarget disposed on the examination table at a second distance from theX-ray source.
 2. The imaging apparatus of claim 1, wherein the memory isfurther configured to store X-ray irradiation conditions mapped to alarge target, a medium target, and a small target, respectively, for theselection of the imaging protocol, and the controller is furtherconfigured to classify a size of the target based on the camera image,as at least one from among the large target, the medium target, and thesmall target, and retrieve, from the memory, the X-ray irradiationconditions corresponding to the classified target.
 3. The imagingapparatus of claim 1, wherein the controller is further configured tocontrol the display to display a graphical user interface (GUI), agraphical object having a shape of the target, and the indicator as agraphical window overlapped with the graphical object, and wherein theGUI is configured to receive the selection of the imaging protocol. 4.The imaging apparatus of claim 3, wherein at least one from among aposition of the graphical window and a size of the graphical window isconfigured to be adjusted via the graphical window, and the controlleris further configured to receive a result of adjusting the at least onefrom among the size of the graphical window and the position of thegraphical window, and store, in the memory, the camera image of thetarget and the indicator indicating the imaging region which has beenadjusted.
 5. The imaging apparatus of claim 1, wherein the cameracomprises a stereo camera.
 6. The imaging apparatus of claim 1, whereinthe controller is further configured to control the display to display,on a first area of a screen, a protocol list for receiving a selectioninput of the imaging protocol, and, based on a camera image displaycommand being input, control the display to display the camera image onthe first area of the screen instead of the displaying the protocollist.
 7. The imaging apparatus of claim 2, wherein the controller isfurther configured to control the display to display a graphical userinterface (GUI) configured to receive settings of the X-ray irradiationconditions for the size of the target for the imaging protocols,respectively, and the memory is further configured to store the X-rayirradiation conditions for the imaging protocols based on the receivedsettings.
 8. The imaging apparatus of claim 1, wherein the controller isfurther configured to determine at least one from among a shape of thetarget and the position of the imaging region of the target by applyingan object recognition algorithm to the camera image.
 9. A method forcontrolling an imaging apparatus, the method comprising: capturing, by acamera, a camera image of a target disposed on an examination tableconfigured to be movable; storing imaging protocols; receivinginformation regarding a selection of an imaging protocol among thestored imaging protocols; identifying a position of an imaging region ofthe target disposed on the examination table based on the camera image,the imaging region corresponding to the selection of the imagingprotocol and the camera image being acquired with the examination tableat a first distance from an X-ray source; controlling a display todisplay the camera image of the target and an indicator indicating theimaging region on the camera image based on the identified position; andgenerating and radiating X-rays toward the target disposed on theexamination table at a second distance from the X-ray source.
 10. Themethod of claim 9, further comprising: storing, in a memory, X-rayirradiation conditions mapped to a large target, a medium target, and asmall target, respectively, for the selection of the imaging protocol;classifying a size of the target based on the camera image, as at leastone from among the large target, the medium target, and the smalltarget; and retrieving, from the memory, the X-ray irradiationconditions corresponding to the classified target.